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Every betting term we use is defined here.
This glossary covers the language of sports betting across the NFL, the NBA, and MLB. Odds and price terms come first, then the value and model words that describe what a projection is worth, then the bet types you meet in every sport, and finally the stat terms specific to each one. Every entry is written in complete sentences, and most link to the tool that uses the term.
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Odds and price
Odds and price terms
These terms describe how a price is written and why it moves. They mean the same thing in every sport we cover.
- American odds
- American odds price a market with a plus or a minus sign. A minus number shows how much you need to risk to win 100, and a plus number shows what 100 of risk would return. The sign tells you immediately which side the market treats as the favorite. Break-Even Calculator →
- Decimal odds
- Decimal odds express a price as the total return on a one unit stake, so 2.50 returns two and a half units including the stake itself. Most markets outside North America quote prices this way, and parlay math is simpler in decimals because you multiply the legs together. Parlay Calculator →
- Implied probability
- Implied probability is the chance of an outcome that a price already contains, found by converting the odds into a percentage. It is the number a projection gets measured against, though it still carries the sportsbook margin until you strip that out. No-Vig Calculator →
- Vig (juice)
- Vig, also called juice, is the margin a sportsbook builds into its prices. It is the reason the two sides of a market add up to more than one hundred percent, and it is the cost of having the market available at all. What is juice? →
- De-vig (no-vig)
- De-vigging strips the sportsbook margin out of a price and leaves the market's fair probability behind. That fair number is the honest benchmark for a model probability, because it compares like with like. No-Vig Calculator →
- Closing line
- The closing line is the last price a market trades at before the event starts. Bettors track it because it is the most informed number a market produces, so comparing the price you took against the close shows whether you beat the market or trailed it. What is closing line value? →
- Line movement
- Line movement is the change in a price between the moment a market opens and any later point in the day. Prices move because new information arrives, because money lands on one side, or because both happen at once. What is line movement? →
- Steam
- Steam is a fast move in one direction that shows up across several sportsbooks at nearly the same time. It usually means respected accounts hit the same side quickly enough that books adjusted together rather than one at a time. Sharp Money Radar →
- Reverse line movement
- Reverse line movement happens when a price moves toward the side that most tickets are not on. It suggests the money behind the smaller ticket count is heavier or better respected than the raw count implies. Sharp Money Radar →
- Limit
- A limit is the largest amount a sportsbook will accept on a market. Limits start low when a number is first posted and rise as the event approaches, which is why an early price can move on relatively little money.
- Push
- A push is a wager that lands exactly on the number, such as a team favored by three that wins by three. Nobody wins or loses, and the stake is returned.
- Void (no action)
- A void, sometimes called no action, is a wager cancelled before it can settle. A postponed game or a player who never takes the field are the common causes, and the exact rules differ by sportsbook and by market.
Value and model
Value and model terms
These are the words we use when a projection meets a price. They carry the same meaning on every board, whether the sport is football, basketball, or baseball.
- Edge
- Edge is the gap between a model's probability and the market's fair, de-vigged probability. A positive edge means the model rates an outcome more likely than the price implies. Edge measures relative value, and it never guarantees a result. How our models work →
- Expected value (EV)
- Expected value is the average result a price would return if the same situation repeated many times. It weighs the amount won when an outcome hits against the amount lost when it misses. EV Calculator →
- Positive EV
- A positive EV situation is one where the fair probability of an outcome sits above what the price implies, so the long-run average of that price is favorable. Positive EV describes the price, not the outcome of any single game. What is positive EV? →
- Fair odds
- Fair odds are the price an outcome would carry once the sportsbook margin is removed. They give you a clean number to compare a projection against. No-Vig Calculator →
- Projection
- A projection is the single expected number a model produces for an outcome before any market price enters the picture. It might be an NFL receiver's yards, an NBA guard's points, or an MLB starter's strikeouts. How our models work →
- Model probability
- Model probability is the chance a model assigns to an outcome, shown next to the sportsbook price so the two can be read side by side. Projections vs. odds →
- Confidence tier
- A confidence tier is a plain-language label such as Elite, Strong, Good, or Moderate attached to a pick, so a board can be sorted by conviction instead of raw numbers. A tier reflects how far the model sits from the market, and it makes no promise about one game. Confidence tiers explained →
- Unit
- A unit is a bettor's standard stake size, expressed as a share of a bankroll rather than a dollar amount. Talking in units lets two people compare results honestly even when they play at very different stakes.
- Return on investment (ROI)
- ROI expresses profit or loss as a percentage of everything staked. It only carries meaning over a large sample, because a short hot or cold run can drag the figure a long way from the truth.
- Variance
- Variance is the natural swing between what a model expects and what actually happens across a small number of games. A sound process can lose for a week and a careless one can win for a week, which is why a handful of results settles very little.
- Sample size
- Sample size is how many observations sit behind a number. A rate built on a few games lurches with every new result, so a small sample is treated as a hint rather than as evidence. Player Prop Trends →
Bet types
Bet types across sports
Every market below exists in the NFL, the NBA, and MLB. Only the unit of scoring changes from one sport to the next.
- Moneyline
- A moneyline market asks which side wins outright, with no spread involved. The price alone carries the difference between the favorite and the underdog. What is a moneyline? →
- Spread (handicap)
- A spread, also called a handicap, gives one side a head start in points or runs so both sides can be priced close to even. The favorite has to win by more than the number, and the underdog can lose by less than it and still cash. What is a point spread? →
- Total (over/under)
- A total is the combined score both teams are expected to produce, offered as an over or an under of a posted number. Football and basketball totals are counted in points, and baseball totals are counted in runs. What is an over/under? →
- Player prop
- A player prop is a market on one player's production rather than on the game result. An NFL receiver's receptions, an NBA guard's points, and an MLB starter's strikeouts are all player props, and each one settles on that player's own number whatever the final score does. NFL Props Board →
- Alternate line
- An alternate line is the same market offered at a different number, with the price adjusted to match. A shorter number costs more, and a longer number pays more. NFL Prop Projections →
- Parlay
- A parlay combines several selections onto one ticket, and every leg has to win for the ticket to pay. The return grows quickly with each added leg, and so does the chance of losing the whole thing. Parlay Calculator →
- Same game parlay
- A same game parlay puts several outcomes from a single game onto one ticket. Because those legs are related, a sportsbook prices them together instead of simply multiplying them. Parlay Calculator →
- Futures
- A futures market settles at the end of a season rather than after a single game, covering outcomes such as a conference winner or a season award. Money stays tied up for months, which is part of the cost.
- Live (in-play)
- A live market is priced while the event is under way, and it reacts to the score, the clock, and injuries. Prices change fast enough that a number can be gone before a ticket confirms.
- Pick em
- A pick em is a market with no favorite, where both sides carry the same price. Daily fantasy apps also use the term for entries where you choose more or less on a player's posted number. DFS Pick'em Optimizer →
NFL
NFL terms
Football props turn on role and opportunity more than on raw talent, so most of these terms describe how a player is used.
- Anytime touchdown
- An anytime touchdown prop asks whether a player scores at any point in the game, rushing or receiving. One trip to the end zone is enough for it to cash. NFL Touchdown Model →
- First touchdown scorer
- A first touchdown scorer market pays only if your player scores the very first touchdown of the game. It is a much narrower outcome than anytime, which is why it carries a longer price. NFL Touchdown Model →
- Receptions
- A receptions prop counts how many passes a player catches, no matter how far the ball travels. Volume in the short passing game matters here more than big plays do. NFL Prop Projections →
- Rushing and receiving yards
- Yardage props ask how far a player advances the ball on the ground or through the air. They reward opportunity and efficiency together, so a heavy workload can carry a modest average per touch, and a light workload needs big plays to clear the same number. NFL Prop Projections →
- Red zone role
- Red zone role describes what a player does inside the opponent's twenty yard line. Scoring chances concentrate there, so a player who takes carries and targets near the goal line reaches the end zone more often than raw yardage suggests. NFL Touchdown Model →
- Game script
- Game script is the way a game is expected to unfold and what that does to play calling. A trailing team throws more, a leading team runs the clock, and those two paths push some props up while pulling others down. NFL Projections →
NBA
NBA terms
Basketball props sit on top of playing time and possessions, so minutes, usage, and pace show up behind almost every number.
- Points props
- A points prop asks how many points a player scores, offered as an over or an under of a posted number. Minutes and usage drive it far more than one hot shooting night does. NBA Points Model →
- Rebounds
- A rebounds prop counts the missed shots a player collects at either end of the floor. Pace, the opponent's shooting, and how much time a player spends near the rim all feed the total. NBA Props Board →
- Assists
- An assists prop counts the passes that lead directly to a made basket. It depends on teammates finishing, which adds noise that the passer cannot control. NBA Props Board →
- Threes made
- A threes made prop counts a player's made three point shots. Attempt volume moves it more reliably than shooting percentage, because percentage swings hard across a single game. NBA Props Board →
- PRA and combo props
- A combo prop adds two or three categories together, most often points, rebounds, and assists, which books post as PRA. Combining categories smooths out the swing of any single one. NBA Prop Projections →
- Minutes
- Minutes are how long a player is on the floor, and they sit underneath every counting prop. A rotation change or foul trouble can move a player's number further than any change in skill would. NBA Prop Projections →
- Usage rate
- Usage rate is the share of a team's possessions a player finishes with a shot, a trip to the line, or a turnover while on the floor. A high usage player simply gets more chances to fill the box score. NBA Points Model →
- Pace
- Pace is the number of possessions a team plays in a game. Faster games create more shots, rebounds, and assists for everyone, so pace lifts or lowers a whole prop board at once. NBA Projections →
- Back to back
- A back to back is the second of two games on consecutive nights. Rest matters in a long season, and teams often manage minutes on the second night. NBA Projections →
- Load management
- Load management is the practice of resting a healthy player to protect them across a long season. It can pull a name off the board late, and it hands the vacated minutes and shots to teammates. NBA Props Board →
MLB
MLB terms
Baseball gives you the deepest public data of the three, so several of these terms measure contact quality rather than results.
- Barrel rate (barrel%)
- Barrel rate is the share of a hitter's batted balls struck at the combination of exit velocity and launch angle that has historically produced extra base hits at a very high rate. A higher barrel rate means a hitter squares the ball up for damage more often. Home Run Model →
- Isolated power (ISO)
- ISO is slugging percentage minus batting average, which strips singles out to measure a hitter's extra base ability. A high ISO points to genuine power rather than empty batting average. Batter Props →
- Expected slugging (xSLG)
- Expected slugging estimates what a hitter's slugging percentage should be based on contact quality rather than the results they happened to get. It helps separate real power from good or bad batted ball luck. Home Run Model →
- Exit velocity
- Exit velocity is how fast the ball leaves the bat, measured in miles per hour. Harder contact carries farther and turns into hits and home runs more often. Home Run Model →
- Hard hit rate
- Hard hit rate is how often a hitter's batted balls leave the bat above a high exit velocity mark. It is a stable signal of contact quality that holds up better across a short stretch than batting average does. Home Run Model →
- HR/9
- HR/9 is home runs allowed per nine innings, a rate that flags how homer prone a pitcher is. Small samples can look extreme, so it is read alongside matchup context rather than on its own. Pitcher HR Targets →
- Strikeout rate (K%)
- Strikeout rate is the share of batters a pitcher strikes out. It captures swing and miss skill without being distorted by how many innings a pitcher happens to throw. Strikeout Props →
- NRFI and YRFI
- NRFI stands for no runs first inning, and it wins when neither team scores in the opening frame. YRFI is the other side of the same market, and it wins as soon as a run crosses the plate in the first. What is NRFI / YRFI? →
- First five innings
- A first five innings market settles on the score after five complete innings, so it turns on the two starting pitchers instead of the bullpens. Bettors use it to sidestep late relief and bench substitutions. Game Projections →
FAQ
Quick answers to common questions
What does plus and minus mean in betting odds?
A minus price marks the favorite and shows how much you need to risk to win 100, so -150 risks 150 to win 100. A plus price marks the underdog and shows what 100 of risk returns, so +150 risks 100 to win 150. The sign is shorthand for which side the market prefers.
What is a unit in betting?
A unit is a bettor's standard stake, expressed as a share of a bankroll rather than a dollar figure. Using units lets two people compare results honestly even when they play at very different stakes.
What is vig in sports betting?
Vig, also called juice, is the margin a sportsbook builds into its prices. It is why the two sides of a market add up to more than one hundred percent, and it is the reason a bettor who picks half of their markets correctly still finishes behind at standard pricing.
What does de-vig mean?
De-vigging removes the sportsbook margin from a price and leaves the market's fair probability. That fair number is what a model probability should be compared against, because it puts both figures on the same footing.
What is a player prop?
A player prop is a market on one player's production instead of the game result, such as an NFL receiver's receptions, an NBA guard's points, or an MLB pitcher's strikeouts. It settles on that player's own number no matter who wins the game.
What is expected value in betting?
Expected value is the average result a price would return if the same situation repeated many times. It weighs the amount won when an outcome hits against the amount lost when it misses, which is why it describes a price rather than a single night.
What is the difference between a parlay and a same game parlay?
A parlay combines selections from different games onto one ticket and needs every leg to win. A same game parlay draws all of its legs from one game, and because those legs are related a sportsbook prices them together instead of simply multiplying them.
Does this glossary cover NFL, NBA, and MLB?
Yes. The odds, value, and bet type sections apply to every sport on the platform, and separate sections define the NFL, NBA, and MLB stat terms that appear on the boards for each one.
See these terms on a live board
Every term in this glossary shows up on the daily boards, where you get the model number beside the market price with the edge called out. The NFL and NBA boards join the rotation as those seasons open.