Prediction Market Glossary
A
AFC (Asian Football Confederation)
The Asian Football Confederation — the regional confederation under FIFA for Asia and Australia. AFC organizes the AFC Asian Cup and the AFC Champions League. Japan, Korea Republic, Iran, and Australia are among the consistent qualifiers from this confederation. For World Cup qualifying, AFC receives 8 direct slots in the 48-team format.
Anytime Goalscorer
A football prop market: will the named player score at any point during the match? The most-bet of the three goalscorer products (alongside first scorer and last scorer) because the math is the most forgiving. Pricing factors include the player's expected minutes, position, set-piece role, and whether they take their team's penalties.
Arbitrage
The practice of placing bets on all possible outcomes of an event across multiple platforms where the combined odds guarantee a profit regardless of the result. Arbitrage opportunities arise when different sportsbooks or prediction markets price the same event differently.
Asian Handicap
A football-specific handicap market that removes the draw outcome by assigning a goal handicap to one side. Lines come in three flavors: whole-goal (e.g. -1, +1, where a draw on the line pushes), half-goal (e.g. -0.5, +0.5, no push possible), and quarter-goal (e.g. -0.25, splits stake across the adjacent zero and half-goal lines for partial outcomes). Asian handicap markets carry tighter book margins than the equivalent 1X2, typically 2-3% versus 5-7%.
ATP
The Association of Tennis Professionals — the men's professional tennis tour. Runs the year-long calendar of tournaments outside of the four Slams, ranging from Masters 1000 down through ATP 500 and 250 events. ATP markets carry deeper handle and tighter pricing than WTA on equivalent matches, primarily because the men's tour draws more total betting volume.
ATP Finals
The year-end ATP tournament featuring the top 8 ranked singles players (and 8 doubles teams) of the year, played in a round-robin format followed by knockout semifinals and final. The format quirks reshape outright pricing — round-robin guarantees three matches even for losing players, and qualification cutoffs in the final group-stage week create sharp price shifts when a top player is eliminated early.
B
Bankroll
The total amount of money a bettor has set aside specifically for betting, separate from other personal finances. Bankroll discipline — sizing bets as percentages of bankroll, not as flat dollar amounts, and treating losses as drawdown rather than incidental expenses — is the foundational concept behind every long-run sustainable betting strategy.
Best-of-3 / Best-of-5
Tennis match-format conventions. ATP and WTA matches outside of men's Slams are best-of-three sets, where the first player to 2 sets wins. Men's singles matches at all four Grand Slams are best-of-five sets, requiring 3 sets to win. Best-of-five gives favorites more variance tolerance — a top player who drops the opening set can still recover — while best-of-three weights early-set momentum more heavily.
Best-of-X (Esports)
The match-format convention in esports where a series is decided by winning a specified number of maps. Best-of-1 is a single map (highest variance); best-of-3 requires winning 2 of 3 maps; best-of-5 requires winning 3 of 5 maps; best-of-7 requires winning 4 of 7 maps. Variance per series decreases as X increases, with heavy favorites more reliable in best-of-5 and best-of-7 formats than in best-of-1 group-stage matches.
Binary Option
A financial instrument with only two possible outcomes: a fixed payout if the underlying condition is met, or nothing if it is not. Prediction market contracts are structurally similar to binary options, settling at either $1.00 or $0.00.
Both Teams to Score (BTTS)
A binary football market: do both teams score at least one goal during the match? Settles Yes if both find the net, No if either keeps a clean sheet or fails to score. Useful for matches between attacking sides on form against defensively struggling opposition, or against the inverse setup. Often paired with the totals market to express layered views (e.g. BTTS Yes + Over 2.5 goals).
Break Point
A point in a tennis service game where the receiver is one point from breaking the server's hold. The margin between elite and merely strong tennis players is often visible in break-point save rate — the percentage of break points the server denies. Break-point conversion is similarly informative for receivers: not every break opportunity is converted, and the gap between sample size and reliability matters.
C
CAF
The Confédération Africaine de Football — the African confederation under FIFA, comprising 54 national associations. CAF organizes the Africa Cup of Nations and the CAF Champions League. Morocco's run to the 2022 World Cup semifinal was the first by an African nation. For World Cup qualifying, CAF receives 9-10 direct slots in the 48-team format.
Cards Market
A football market on the total disciplinary cards in a match (yellow + red, with red typically counting as 2). Standard top-flight European lines sit around 4.5 to 5.5. The three main price-moving inputs are referee tendency (some officials average 4 cards a match, others 6), match context (derbies and high-stakes fixtures produce more bookings), and style matchup (pressing teams against slow build-up sides see more challenges).
Champions League
The UEFA Champions League — the top continental club competition in European football, run by the Union of European Football Associations (UEFA). 36 clubs (since the 2024-25 reform; previously 32) qualify based on UEFA coefficient slots and a multi-round qualifying tournament. The competition runs from August through May or June, with a single 36-team league phase replacing the old group stage. Top 8 advance directly to the Round of 16; 9th-24th enter a knockout playoff round; 25th-36th are eliminated.
Closing Line Value (CLV)
The difference between the price a bettor took on a market and the closing line of that same market. A bettor who consistently beats the closing line (entered at -6 and the market closed at -7) is showing positive CLV — typically a strong predictor of long-run profitability. CLV is the most reliable single metric for distinguishing skilled bettors from variance-driven ones, used by sportsbooks to identify sharp accounts.
CONCACAF
The Confederation of North, Central American and Caribbean Association Football — the regional confederation under FIFA covering North America, Central America, and the Caribbean. CONCACAF organizes the Gold Cup and the CONCACAF Champions Cup. Mexico and the United States are the most prominent national teams. For World Cup qualifying, CONCACAF receives 6 direct slots plus host slots in the 48-team format.
Conference League
UEFA's third-tier continental club competition, introduced in the 2021-22 season. Premier League's 6th or 7th finisher may qualify in some seasons, depending on cup-winner overlaps. Less prestigious and lower-handle than the Champions League or Europa League, but still produces real fixture-density effects on participating clubs.
CONMEBOL
The Confederación Sudamericana de Fútbol — the South American confederation under FIFA, comprising 10 national associations. CONMEBOL organizes the Copa América and Copa Libertadores. Brazil and Argentina are the dominant national teams; both have multiple World Cup titles. For World Cup qualifying, CONMEBOL receives 6 direct slots in the 48-team format.
Contract
In prediction markets, a contract is a tradable instrument that pays out based on the outcome of a specified event. Each contract typically settles at $1.00 if the event occurs or $0.00 if it does not. Contracts are bought and sold on an exchange.
Corners Market
A football market on total corners awarded in a match. Standard top-flight lines sit around 9.5 or 10.5. Corners are produced by attacking pressure and defensive scrambles; teams that play wide-forward systems and cross frequently generate them at higher rates than teams that play through the middle. Match-state shifts the rate sharply — a team chasing a goal in the final 20 minutes generates corners well above season average.
Correct Score
A football market on the exact final scoreline (e.g. 2-1 home win). Pays well when right because the field of plausible scorelines is large and the books bake substantial margin into each line. Best used when a bettor has a specific tactical thesis (e.g. one side to keep a clean sheet, total goals to land at 3) rather than as a casual pick.
Court Surface
The playing surface in tennis, classified into three main types on the ATP and WTA tours: clay (slowest, highest bounce, longest rallies — Roland Garros), grass (fastest traditional surface, lowest bounce, serve-dominant — Wimbledon), and hard court (intermediate pace, truer bounce — Australian Open and US Open). Surface is the single biggest contextual variable in tennis betting, and a player's ranking can mislead significantly across surface transitions.
CS2 (Counter-Strike 2)
Counter-Strike 2 — the latest installment in the Counter-Strike series, a 5v5 tactical first-person shooter developed by Valve. Released in 2023 as the successor to CS:GO. Major tournaments are organized by independent organizers (ESL, BLAST, PGL) with PGL Majors as the most prestigious annual events. The deepest betting market in any esports, with the largest English-language handle.
D
Deposit Match
A sportsbook promotion where the operator matches a percentage of your initial deposit with bonus funds. A 100% deposit match up to $500 means if you deposit $500, you receive an additional $500 in bonus funds, typically subject to rollover requirements.
Dota 2
Dota 2 — a 5v5 MOBA developed by Valve. The annual championship — The International (TI) — features the largest single-tournament prize pool in esports history. Dota 2 patches are mechanically transformative, regularly adding new heroes and reshaping core game systems. Chinese, European, and CIS teams have historically dominated TI, with regional dominance shifting across cycles.
Double Chance
A football market that lets you back two of the three 1X2 outcomes on a single ticket. The three combinations are 1X (home win or draw), X2 (away win or draw), and 12 (home or away — the no-draw bet). Pays less than a straight win bet but useful when you want to fade one specific outcome rather than back another.
Draw
The bracket structure of a knockout tournament, listing every player and the path of matches they must win to reach the final. Tennis Slams use a 128-player single-elimination draw on each side (men's and women's), requiring 7 rounds to win. The draw is constructed using seeding rules that separate top-ranked players into different bracket sections, plus randomized placement of unseeded players, wild cards, and qualifiers. Bracket position within the draw — whether a top seed faces tough opposition early or coasts through R128-R32 — is a meaningful pre-tournament betting input.
Draw No Bet (DNB)
A football two-way market: bet one side to win, with stake refunded if the match ends in a draw. Functionally equivalent to the Asian handicap zero-line. Trades shorter odds for the draw insurance and is useful in matches you read as competitive but where the draw is a real possibility.
E
EFL Cup (League Cup)
The secondary domestic cup competition in English football — sponsored variously across cycles as the Carabao Cup, Capital One Cup, Worthington Cup, etc. Run by the English Football League (EFL), open to all 92 clubs in the top four divisions. Premier League clubs enter at the second round; matches are played midweek throughout the season, with the final at Wembley in late February or early March. Winning the EFL Cup grants Europa League qualification.
Europa League
UEFA's second-tier continental club competition, played in parallel with the Champions League. Qualification routes vary by season but typically include the Premier League's 5th-place finisher (in non-expanded UEFA-coefficient years), the FA Cup winner, and the EFL Cup winner. Matches are played on Thursday nights, which creates a 3-day-rest gap before Sunday Premier League fixtures — a different rotation pattern than UCL clubs face.
Event Contract
A specific type of financial contract where the payout is determined by the outcome of a real-world event, such as an election result, economic indicator, or sports outcome. Event contracts are the primary instrument traded on CFTC-regulated platforms like Kalshi.
Expected Value (EV)
The mathematical expectation of a bet's return per unit staked over the long run. Positive EV means the bet's true probability of winning exceeds the implied probability of the price; negative EV means the price is unfavorable. Long-run profitable betting requires a positive-EV process applied across enough volume that variance evens out — a winning percentage in the short term is not the same as a positive EV.
Extra Time
Two additional 15-minute halves played in football knockout matches (cup competitions, tournament eliminations) when regulation ends in a draw. Standard pre-match 1X2 betting settles at the end of regulation, not after extra time, so a knockout match resolved in extra time still settles the regulation market as a draw. Outright tournament markets and 'to qualify' markets resolve over the full match including extra time and penalties.
F
FA Cup
The Football Association Challenge Cup — the oldest football competition in the world, first held in 1871. A knockout tournament run by the Football Association (FA) of England, open to clubs across the entire English football pyramid. Premier League clubs enter at the third round in early January. The final is played at Wembley Stadium in late May. Winning the FA Cup grants Europa League qualification for the following season.
FIFA
The Fédération Internationale de Football Association — the international governing body of football, headquartered in Zürich, Switzerland. FIFA organizes the World Cup, the Women's World Cup, and the Confederations Cup, and recognizes six continental confederations that run regional competitions. For betting purposes, FIFA sets the rules of competition (squad sizes, substitution allowances, qualifying formats) that shape every tournament market.
First Goalscorer
A football prop on which player will score the first goal of the match. Carries wider book margins than anytime goalscorer because the variance is higher — an own goal, a late substitute, or a defender from a corner can all flip the market. Stake size in this product should typically be smaller than a standard unit.
First-Serve Percentage
The percentage of first serves a tennis player lands in the service box. A player landing first serves at a high rate (typically 60-65%+ for top professionals) wins more cheap service points and faces fewer break-point situations. A struggling first-serve percentage is one of the earliest signals of an off-day or a player working through a physical limitation.
Fixture Density
The compressed schedule a football team faces during stretches with multiple competitions overlapping (domestic league + Champions League + cup). High fixture density forces squad rotation, especially when a team is playing its third match in eight days. The starting eleven on a Sunday is rarely the one on a Wednesday. The days-of-rest gap between two opposing teams is a real betting input the market does not always price in fully.
Free Bet
A promotional credit from a sportsbook that allows you to place a wager without risking your own money. If the free bet wins, you receive the profit but typically not the original stake amount. Free bets usually have an expiration date and may be restricted to certain bet types or minimum odds.
G
Golden Boot
The trophy awarded to the top scorer of a major football tournament (most prominently the FIFA World Cup, but also the Premier League, Champions League, and other competitions). World Cup Golden Boot winners typically score 5-6 goals across the tournament, occasionally reaching 7-8 in higher-scoring editions. Position, tournament longevity, penalty-taker status, and set-piece duty are the structural inputs to Golden Boot betting markets.
Grand Slam
The four most prestigious tennis tournaments held annually: the Australian Open (January, hard court), Roland Garros / French Open (May-June, clay), Wimbledon (June-July, grass), and the US Open (August-September, hard court). The biggest prize money, the deepest betting handle, and the most accurate book pricing — Slam markets are among the hardest places to find a sustained edge.
Group Stage
The opening round of a football tournament where teams are placed in groups (typically 4 teams per group) and play each other in a round-robin format. Teams earn 3 points for a win, 1 for a draw, 0 for a loss. The top finishers (varies by tournament: top 2, or top 2 + best third-placed teams) advance to the knockout stage. The group stage is the most-priced tournament market in the early weeks because every match generates qualifying implications.
H
Half-Time / Full-Time
A combined football market predicting both the leader at half-time and the final result. Nine common combinations (Home/Home, Home/Draw, Home/Away, Draw/Home, etc.) make this a high-variance, high-payout product. It is functionally a parlay, and books price it accordingly — the margin is wider than betting both legs separately.
Handicap Games (Tennis)
A tennis handicap market that gives one player a games head-start (e.g. +3.5 games to the underdog). Lets a bettor back a weak favorite at a better price by requiring them to win by a margin, or take a strong underdog with a games cushion built in. Functionally similar to football's Asian handicap but applied to tennis games rather than goals.
Hedging
Placing a bet on the opposite side of an existing wager to reduce risk or lock in a guaranteed profit. Common in futures bets (e.g., hedging a Super Bowl futures bet when your team reaches the championship) and in prediction markets where you can sell your position.
Hold of Serve
Winning a service game in tennis, meaning the server wins enough points to take the game without being broken. Top-level players hold serve at high rates — often above 80% on faster surfaces — and the structural advantage of serving compounds across a match. The break-vs-hold dynamic is the single most important rhythm in tennis match betting.
I
Implied Probability
The probability of an outcome as reflected by the current odds or contract price. For American odds, implied probability is calculated as |odds| / (|odds| + 100) for favorites, or 100 / (odds + 100) for underdogs. For prediction market contracts, the price directly equals the implied probability.
K
Kelly Criterion
A formula for optimal bet sizing given a known edge and odds. The Kelly fraction is (p × b - q) / b, where p is the probability of winning, q is 1-p, and b is the decimal odds minus 1. Pure Kelly maximizes long-run bankroll growth but produces volatile equity curves; most professional bettors use fractional Kelly (typically half Kelly) to dampen variance while preserving most of the growth.
Key Numbers
Specific point margins in football (NFL especially) that occur with high frequency because of the scoring system. The most common winning margins are 3 (a field goal), 7 (a touchdown plus extra point), 10 (a touchdown plus a field goal), and 14 (two touchdowns). Spreads landing exactly on key numbers produce different push probabilities than spreads landing off them. Buying or selling half a point through a key number — typically 3 or 7 — has measurable expected-value implications.
Knockout (KO)
A combat-sports finish where one fighter is rendered unconscious or unable to continue by the other fighter's strikes, ending the bout immediately. KOs typically result from a clean punch, kick, knee, or elbow. The KO market in combat sports betting refers to the prop market on whether a bout will end via knockout (separate from technical knockout, decision, or submission).
Knockout Stage
The single-elimination phase of a football tournament that follows the group stage. Standard rounds in modern World Cup format are: Round of 32 (R32, new in 2026), Round of 16 (R16), Quarterfinal (QF), Semifinal (SF), and Final. Each match is decided by 90 minutes of regulation, plus extra time and penalty shootout if tied. Pre-match 1X2 markets settle at end of regulation; 'to advance' markets settle over the full match including ET and penalties.
L
Last Goalscorer
A football prop on which player will score the final goal of the match. Like first-goalscorer, the variance is high and the margins are wide. The market settles only after the final whistle, so a 90th-minute substitute or stoppage-time goal can resolve the bet against you in ways pre-match analysis cannot anticipate.
League of Legends (LoL)
League of Legends — a 5v5 multiplayer online battle arena (MOBA) developed by Riot Games. Major leagues run regionally (LCK in Korea, LPL in China, LEC in Europe, LCS in North America), feeding into the annual World Championship in autumn. The largest esports betting handle outside of CS2, with deep market depth on regional leagues and Worlds matches.
League Phase
The opening round of the Champions League since the 2024-25 reform — a single 36-team table where each club plays 8 different opponents (4 home, 4 away) drawn from 4 seeded pots. Replaced the previous 8-group, 4-team-per-group format. The top 8 finishers in the league phase advance directly to the Round of 16; 9th-24th finishers enter a knockout playoff round; 25th-36th are eliminated. The league phase runs from September through January.
Limit Order
An order to buy or sell a contract at a specified price or better. Unlike a market order that executes immediately at the best available price, a limit order only fills when the market reaches your price. Limit orders are essential for managing execution costs on prediction market exchanges.
Line Movement
The change in a betting line from open to close, driven by bet flow, late-arriving information (injuries, weather, lineups), and book risk management. The closing line is generally the sharpest price of any market because all the day's information has been integrated. Bettors whose entries consistently beat closing lines are the most reliable predictors of long-run profitability — a metric known as 'closing line value' or CLV.
Liquidity
A measure of how easily contracts can be bought or sold at stable prices. High liquidity means large orders can be filled without significantly moving the price. Low liquidity leads to wider bid-ask spreads and potential slippage on trades.
M
Map Veto
The pre-match process in CS2 and Valorant where teams alternate banning and selecting maps from the active map pool, producing the specific maps that will be played in the series. Each team's map preferences and weaknesses shape their veto strategy. The maps that result from the veto are not random — they reflect deliberate strategic choices, and bettors who track team map-pool strengths can identify favorable matchups before the match begins.
Market Maker
An entity or trader that provides liquidity to a market by simultaneously posting buy and sell orders. Market makers profit from the bid-ask spread. On prediction market exchanges like Kalshi, market makers help ensure there is always someone to trade against.
Masters 1000
The tier of ATP tournaments below the four Grand Slams. Mandatory for most top players, with elite fields and deep markets. The nine Masters 1000 events run across hard, clay, and grass throughout the year. The WTA equivalent is WTA 1000. Markets are well-priced but slightly less tight than at Slams.
Meta
The dominant strategies, character/champion picks, and tactical patterns favored by the current state of an esports game. The meta shifts when patches change game balance, when professional teams discover new strategies, or when one team's success forces others to adapt. Meta volatility is one of the most distinctive features of esports betting — a team optimized for the previous meta may struggle when the meta shifts in a different direction.
Method of Victory
A combat-sports prop market on how a bout will end. Standard options for MMA: KO, TKO, submission, or judges' decision. Standard options for boxing: KO/TKO, decision, or draw. Method-of-victory markets carry wider book margins (15-25%) than the moneyline because the variance is higher and the public over-bets famous knockout artists.
MMA
Mixed martial arts — a combat-sports discipline combining striking (boxing, kickboxing, muay thai) with grappling (wrestling, brazilian jiu-jitsu). Bouts can end by knockout (KO), technical knockout (TKO), submission, or judges' decision. The dominant MMA promotion is the UFC; secondary promotions include Bellator, ONE Championship, and the season-format PFL.
Moneyline
A bet on which team or participant will win an event outright, without a point spread. Favorites have negative odds (e.g., -150) and underdogs have positive odds (e.g., +200). The moneyline is the simplest form of sports wagering.
N
New Manager Bounce
The short-term performance lift a struggling football club typically shows in the first 3-5 matches under a new manager. The effect is real but small — the public and the market both tend to overprice it, particularly in the second and third matches when the bounce begins to fade and the underlying team-quality issues reappear. Fading the new-manager favorite line in their second or third match is a recurring soft spot in the market.
NFL
The National Football League — the top professional American football competition in the United States. 32 teams across two conferences (AFC and NFC), 17-game regular season, 14-team playoff bracket, Super Bowl as the championship. The highest-handle league in any single sport globally, with deep market depth and tight spread vig (4-6%). Public-money flow patterns produce predictable mispricings on home favorites, primetime overs, and recently-winning teams.
O
OFC
The Oceania Football Confederation — the Oceanian confederation under FIFA, the smallest of the six regional confederations. New Zealand is the dominant national team. For World Cup qualifying, OFC receives 1 direct slot plus 1 inter-confederation playoff slot in the 48-team format.
Open Interest
The total number of outstanding contracts in a prediction market that have not yet been settled. High open interest indicates strong participation and typically corresponds with better liquidity. Open interest changes when new contracts are created or existing positions are closed.
Over/Under
Also called a totals bet. A wager on whether the combined score of both teams in a game will be over or under a number set by the sportsbook. For example, an over/under of 48.5 in an NFL game means you bet on whether the total points scored will exceed or fall below 48.5.
Overround
The amount by which a market's implied probabilities sum above 100%, representing the book's margin. A football 1X2 market with implied probabilities of 60% / 28% / 18% has an overround of 6%. Overround is a synonym for vig in three-way markets; it is the structural reason markets cannot be exploited by simply backing every outcome.
P
Parlay
A single wager that combines two or more individual bets into one. All selections must win for the parlay to pay out. Parlays offer higher potential payouts than individual bets but carry significantly more risk due to the compounding probability of multiple outcomes.
Patch (Esports)
A software update released by a game's developer that adjusts game balance — weapon stats, character abilities, map dynamics, or core mechanics. Patches are released on a recurring schedule (more frequent in League of Legends, less frequent in CS2). Patches reshape the competitive meta — the dominant strategies and team compositions — and produce structural betting opportunities in the 1-3 matches following each patch as teams adapt at different rates.
Penalty Shootout
The tiebreaker procedure used in football knockout matches still level after extra time. Each team takes five penalty kicks alternating, with sudden death from the sixth onward if needed. Conversion rates in shootouts hover around the high 70s percent. The shootout decides which team advances but does not affect the result for pre-match 1X2 settlement.
PFL
The Professional Fighters League — an MMA promotion with a distinctive season-and-tournament format. Fighters compete across a regular season, accumulating points based on bout outcomes and finishes. Top finishers advance to a playoff bracket; the playoff produces semifinalists who meet in a championship final. The format includes single-night tournaments where a fighter may compete in two bouts in one evening. Champions receive substantial year-end purses.
Point Spread
A handicap market used in American sports (NFL, NBA, NCAA) where the favorite must win by more than a specified margin and the underdog gets that margin as a head start. Standard vig is -110 on both sides, equivalent to about 4.5% margin. The point spread is the central NFL betting product, drawing more handle than the moneyline. A spread of -7 means the favorite must win by 8+ points; +7 means the underdog can lose by 6 or fewer (or win outright) and still cover.
Premier League
The top tier of professional football in England, formally the English Premier League (EPL). 20 clubs play 38 matches each (home and away vs. all 19 others) from August to May. The top 4-5 clubs qualify for the UEFA Champions League the following season; the bottom 3 are relegated to the EFL Championship. The most-bet domestic football league globally, with the deepest market depth and the tightest book margins on top-tier matches.
Public Money
Bets placed by recreational bettors, often on the most popular team or the bigger favorite. Public money tends to move lines in predictable ways — toward home favorites, toward primetime games, toward overs — that informed bettors can fade when the line has moved further than the underlying probability justifies. Also called square money.
Push
A bet outcome where the result lands exactly on the line, returning the bettor's stake without win or loss. Common in spread and total markets where lines are whole numbers (e.g. a -1 spread that resolves with a one-goal margin pushes; a 2.5 total that resolves at exactly 2 or 3 cannot push). Half-goal and half-point lines exist specifically to prevent pushes.
Q
Qualifier
A player who reaches the main draw of a tournament by winning a pre-tournament qualifying competition rather than by direct ranking entry. At Slams, the qualifying competition runs the week before the main draw and produces 16 qualifiers (per gender) who fill out the 128-player field. Qualifiers enter the main draw with multiple recent matches on the tournament's surface — a structural advantage over seeded players coming off a different surface.
R
Rollover
A wagering requirement attached to a sportsbook bonus. Before you can withdraw bonus funds or winnings derived from a bonus, you must wager a specified multiple of the bonus amount. For example, a 5x rollover on a $200 bonus means you must place $1,000 in total wagers before withdrawing.
S
Set Betting
A tennis market on the exact scoreline in sets — for example, Player A wins 2-0 or 2-1, or in best-of-five Slams, 3-0, 3-1, or 3-2. Carries higher variance than the moneyline because the field of possible scorelines is larger, and books bake more margin into the lines. Useful when you have a directional view on competitiveness that the moneyline price does not fully capture.
Settlement
The process by which a prediction market contract or sports bet is resolved and paid out. In prediction markets, contracts settle at $1.00 or $0.00 based on the verified outcome of the event. Settlement rules, including the data source used for verification, are defined in the contract terms.
Sharp Money
Bets placed by professional or otherwise informed bettors who consistently extract long-run value from markets. Sharp money is identifiable by the books through bet timing (early or late on lines), bet size, and account history. Markets typically move toward the side that sharps are on, which is why following late line movement on a market is a more reliable signal than reading public sentiment.
Spread
The point differential set by oddsmakers to create a balanced market between two teams. The favorite must win by more than the spread for a bet on them to pay out, while the underdog can lose by less than the spread (or win outright) for a bet on them to cash.
Steam Move
A sudden, sharp move in a betting line driven by a wave of large bets across multiple books at roughly the same time. Steam typically signals coordinated sharp action and is itself a market-moving event — bookmakers chase steam, recreational bettors react to it, and the line settles at a new level reflecting the new information. Identifying steam in real time requires line-tracking infrastructure most casual bettors do not have.
Stoppage Time
The minutes added by the referee at the end of each half of a football match to compensate for in-game delays — substitutions, injuries, video reviews, time-wasting. Also called injury time or added time. Pre-match betting settles at the end of regulation including stoppage, so a 90th-minute equalizer that arrives in the 4th minute of stoppage time still settles the regulation market.
Submission
A combat-sports finish (in MMA, not boxing) where one fighter forces the other to verbally or physically tap out, typically due to a chokehold, joint lock, or other grappling technique. The referee then stops the bout. Submission specialists — fighters with strong jiu-jitsu or wrestling backgrounds — produce structural matchup advantages against opponents with weaker ground defense.
Super Bowl
The annual championship game of the National Football League (NFL), played in early February at a neutral pre-selected venue. The largest single-game betting market in any sport globally. Pre-game lines move across a full two-week window between the conference championships and the Super Bowl itself. Hundreds of prop markets are offered, ranging from genuine betting markets (player props, MVP futures) to entertainment-driven novelty props (national anthem length, halftime show props) with very wide margins.
T
Technical Knockout (TKO)
A combat-sports finish where the referee, ringside doctor, or fighter's corner stops the bout because one fighter cannot intelligently defend themselves. Unlike a KO (which ends with the fighter unconscious or visibly unable to continue), a TKO ends with the fighter standing but no longer competitive. Some books combine KO and TKO into a single 'KO/TKO' line for the method-of-victory market.
Tiebreak
The standard tiebreaker game played in tennis when a set reaches 6-6, won by the first player to 7 points with a margin of 2. The exception in most Slams is the final set, which historically used advantage scoring — though most tournaments now resolve the final set with a tiebreak at either 6-6 or 12-12 depending on the event. Tiebreak performance is a leading indicator of match-pressure resilience.
Total Games
A tennis market on the over/under of total games played in a match. Books set a line (e.g. 21.5 total games) and bettors pick over or under. The line moves based on expected match competitiveness — close best-of-three matches typically run 22-26 games, while a straight-sets blowout may end in 18-20. Useful when you have a view on how competitive a match will be, separate from who wins.
Transfer Window
The period during which football clubs can register player transfers. European leagues operate a summer window (closing late August) and a winter window (January). Teams that bought late and bought poorly often drag through the following month. Teams that lost a key player after the window closed cannot replace them and play short of cover until the next window opens. Markets typically take 2-3 matches to fully reprice these effects.
U
UEFA
The Union of European Football Associations — the European confederation under FIFA. UEFA runs the Champions League, the Europa League, the Conference League, and the European Championship (Euros). For betting purposes, UEFA's club competitions overlap with domestic leagues throughout most of the season, creating fixture density and squad rotation effects.
UFC
The Ultimate Fighting Championship — the dominant promotion in mixed martial arts (MMA), founded in 1993. UFC organizes events across multiple weight classes, hosts pay-per-view (PPV) events for major bouts, and recognizes its own champions per weight class. The deepest betting market in MMA, with tighter margins on main-event matches than on preliminary cards. Public-money flow on UFC events systematically over-prices famous fighters relative to matchup analysis.
Unit
A bettor's standard stake size, typically expressed as a percentage of total bankroll. Conventional unit sizing is 1-2% of bankroll per bet. Flat-unit betting (every bet the same size) prevents emotional escalation after losing runs and is the only stake structure where the math of expected value catches up to actual results across a meaningful sample.
V
Valorant
Valorant — a 5v5 tactical first-person shooter developed by Riot Games, released in 2020. Combines the round-based economy of Counter-Strike with character abilities reminiscent of MOBAs. The Valorant Champions Tour (VCT) runs as the primary competitive structure, with regional and global stages culminating in Champions in late summer. The newest major esports betting market, less crystallized than CS2 / LoL / Dota 2.
VAR (Video Assistant Referee)
The video review system used in most top-flight football leagues to assist the on-field referee on goal decisions, penalties, red cards, and mistaken identity. VAR has tightened offside calls and increased the rate of overturned penalty decisions in leagues that use it. Reviews extend stoppage time and create brief windows of uncertainty in live betting markets while the decision is pending.
Variance
The natural distribution of outcomes around an expected value. Even a positive-EV bettor will experience losing streaks driven by variance, and even a negative-EV bettor will hit hot streaks. Sample size matters: a 100-bet sample is too small to distinguish signal from variance for any but the largest edges. Bankroll sizing assumes variance and is built to absorb drawdowns without forcing the bettor to deviate from the long-run process.
Vig / Juice
The commission or margin built into sportsbook odds. Also called the vigorish. Standard vig is -110 on both sides of a spread bet, meaning you must risk $110 to win $100. The vig is how sportsbooks guarantee profit regardless of the outcome. Lower vig means better value for bettors.
W
Weight Class
Mandatory weight categories that combat-sports fighters must compete within. Each promotion (UFC, boxing sanctioning bodies, PFL) defines weight classes ranging from strawweight (lightest) through heavyweight. Lighter classes produce more decisions and longer bouts on average; heavier classes produce more knockouts and shorter bouts. Heavyweight is structurally the highest-variance class because of single-strike finishing power.
Wild Card
A tournament entry granted by the organizers outside the standard ranking-based qualification path. Wild cards typically go to local players (a Brit at Wimbledon, an American at the US Open), to returning veterans coming back from injury, or to top juniors making their senior debut. Wild card recipients are unseeded — they slot into the draw against seeded players, often producing first-round matchups where the wild card has surface-specific match practice the seed lacks. The structural mismatch is a recurring source of first-round upsets at Slams.
WTA
The Women's Tennis Association — the women's professional tennis tour. Like the ATP, it runs the calendar outside of Slams across WTA 1000, 500, and 250 events. WTA markets typically run thinner than ATP markets, which means the books lean more on ranking and less on granular matchup data — occasionally creating soft prices for bettors willing to do the surface and form research.
Y
Yes/No Contract
The standard contract format on prediction market exchanges. A \"Yes\" contract pays $1.00 if the event occurs, and a \"No\" contract pays $1.00 if it does not. The prices of Yes and No contracts for the same event always sum to approximately $1.00 (before fees).