- American Odds
- The standard odds format used in the United States. Positive odds (+150) show profit on a $100 bet. Negative odds (−150) show how much you must bet to win $100. Also called "moneyline odds."
- Air Yards (NFL)
- The distance a forward pass travels through the air from the line of scrimmage to the catch point (or intended catch point). A key input for WR receiving yards models — more air yards = deeper targets = higher ceiling.
- Barrel / Barrel%
- A Statcast classification for batted balls with both a high exit velocity (98+ mph) and an ideal launch angle. Barrel% is the percentage of a batter's batted balls classified as barrels. It's the strongest predictor of HR production — more predictive than even HR count itself.
- Book / Sportsbook
- The entity accepting and paying out bets. DraftKings, FanDuel, BetMGM, etc. "The book" sets lines. "Beating the book" means winning more than the vig erases over time.
- Bankroll
- The total funds you have set aside for betting. Proper bankroll management (flat betting 1–3% per play) is the single most important factor in long-term survival as a bettor.
- Closing Line Value (CLV)
- The difference between the odds you bet and where the line closes at game time. If you bet +240 and it closes at +190, you beat the closing line by 50 cents — that's positive CLV. It's the best long-term indicator of a skilled bettor, because sharp money moves closing lines toward true probability.
- CSW% (Called Strikes + Whiffs)
- Called strikes plus swinging strikes divided by total pitches. A comprehensive "miss rate" metric for pitchers that captures both umpire-favorable pitches and pure swing-and-miss. A core input in PropBetEdge's K-Score.
- Cover / Covered
- When the favored team wins by more than the spread, or the underdog loses by fewer points than the spread. "Did you cover?" means did your bet win.
- Dead Money
- Casual money bet by recreational bettors that moves lines in the wrong direction relative to true probability. Sharp bettors identify and fade dead money — it's why public-facing teams often have worse odds than the market should imply.
- DFS (Daily Fantasy Sports)
- Contests (DraftKings, FanDuel) where you build a lineup within a salary cap and compete against other players. Prop betting and DFS use many of the same underlying metrics — Statcast data, target share, usage rate — but have different optimal strategies.
- Expected Value (EV)
- The average return per bet over infinite repetitions. EV = (Win Probability × Profit) − (Loss Probability × Stake). A +EV bet has positive expected value — it returns profit over time even if it loses today. Identifying +EV is the entire goal of prop betting research.
- Exit Velocity (EV)
- The speed of the ball off the bat in miles per hour, measured by Statcast. Average exit velocity of 90+ mph is solid; 95+ is elite. A primary input in HR probability models — harder contact = more power.
- Flat Betting
- Betting the same fixed amount on every play regardless of confidence level. The mathematically correct approach for most bettors. Avoids the trap of betting more on "sure things" — which increases variance and destroys bankrolls in cold streaks.
- Fade / Fading
- Betting against a particular side or pick. "Fading the public" means taking the opposite side of heavy public action, betting that the book has shaded the line and the public side is overpriced.
- Groundball Rate (GB%)
- The percentage of batted balls that are ground balls. High GB% pitchers suppress HR props because ground balls don't leave the park. A key pitcher input for batter HR models — you don't want to fade a barrel machine hitting against a 55% GB pitcher.
- Hard Hit Rate (Hard Hit%)
- The percentage of batted balls hit at 95+ mph exit velocity. A simpler version of the barrel metric — less precise but easier to compute. Used as a secondary power indicator in PropBetEdge's batter models.
- Handle
- The total dollar amount wagered on an event or market. High-handle markets (NFL, major MLB games) have sharper lines because more money creates more efficient pricing. Smaller markets (like daily MLB player props) can have softer lines.
- Implied Probability
- The probability of an outcome implied by the odds, after removing the vig. For +150: 100/(150+100) = 40%. For −130: 130/(130+100) = 56.5%. When PropBetEdge's model probability exceeds the implied probability, there's potential +EV.
- K-Score
- PropBetEdge's proprietary 0–100 score for pitcher strikeout upside. Combines swinging strike rate (30%), CSW% (20%), stuff quality (15%), opposing lineup K rate (20%), umpire K tendency (10%), and recent form (5%). 80+ = elite K prop candidate.
- K Prop (Strikeout Prop)
- A bet on how many strikeouts a pitcher will record. Typically set at 5.5, 6.5, or 7.5 Ks. High-variance but exploitable — swinging strike rate and umpire assignment are predictive inputs the market often underweights.
- Lambda (λ)
- The expected rate parameter in a Poisson distribution — the average number of events expected in the interval. In PropBetEdge's HR model, lambda is the expected home runs per game for a specific batter in a specific matchup. Everything in the model flows through lambda.
- Line Movement
- The change in odds from when they open to when the game starts. Sharp money (professional bettors) moves lines toward true probability. Public money often moves lines away from it. Understanding why a line moves is more valuable than the move itself.
- Model Odds
- Odds generated by PropBetEdge's Poisson probability model, independent of any sportsbook. Model odds represent our estimate of true fair-value probability. When model odds are higher than book odds (more likely), the bet has potential positive EV.
- Moneyline (ML)
- A straight bet on who wins the game with no point spread. The favorite is negative (−150) and the underdog is positive (+130). Most prop bets use moneyline-style odds regardless of the market.
- Overround / Vig / Juice
- The sportsbook's built-in commission. On a two-sided market, the sum of both implied probabilities exceeds 100% — that excess is the vig. At −110/−110 odds, the overround is ~4.7%. This is the house edge you're fighting against.
- Over / Under (O/U)
- The two sides of a prop bet line. You bet OVER if you think the player will exceed the set total; UNDER if you think they'll fall short. The line is the threshold. PropBetEdge models OVER probability for HR, total bases, strikeouts, and hits.
- Park Factor
- A multiplier for how much a ballpark favors hitters or pitchers relative to average (100 = neutral). Coors Field (≈120) dramatically inflates HR and run production. Petco Park in San Diego (≈82) suppresses offense. PropBetEdge adjusts all lambda calculations by park factor and real-time weather.
- Platoon Split
- The difference in a batter's performance against right-handed vs. left-handed pitchers (or vice versa). Most batters perform better against opposite-hand pitchers. PropBetEdge applies platoon adjustment factors when calculating lambda.
- Poisson Distribution
- A probability distribution for the number of times an event occurs in a fixed interval, given an average rate (lambda). P(k) = (λᵏ × e^−λ) / k!. PropBetEdge uses this to convert Statcast-derived expected rates into game-level probability distributions for HR, Ks, TB, and hits.
- Prop Bet (Proposition Bet)
- A wager on a specific statistical outcome within a game, independent of the final result. Player props (individual stats) and game props (team stats) are the two categories. PropBetEdge focuses on player props — the market with the most exploitable edges.
- Reverse Line Movement (RLM)
- When a line moves opposite to public betting percentages. If 80% of bets are on the OVER but the line moves toward UNDER, sharp money is on the UNDER and the books are moving to protect themselves. RLM is a sharp indicator signal.
- Sharp / Sharp Money
- Professional or sophisticated bettors who bet large amounts based on analytical edges. Sharp action moves lines toward true probability. Identifying whether line movement is driven by sharps or public is a key skill in prop betting.
- Statcast
- MLB's ball-tracking system that measures every aspect of every play — exit velocity, launch angle, sprint speed, pitch velocity and spin, fielder reaction time. PropBetEdge ingests Statcast data nightly for 287 batters and 200+ pitchers into its own Supabase database.
- SwStr% (Swinging Strike Rate)
- The percentage of all pitches that result in a swinging strike (the batter swings and misses). The single strongest predictor of strikeouts. Elite whiff rates are 15%+. A primary input in PropBetEdge's K-Score.
- Steam Move
- A sudden, coordinated movement across multiple books on the same side of a bet. Indicates sharp money hitting all available markets simultaneously. Steam moves often precede significant line movement.
- Target Share (NFL/NBA)
- The percentage of a team's total pass attempts directed at a specific receiver. High target share = high floor for receiving stats. A key input for WR/TE receiving yards and receptions props.
- Total Bases (TB)
- A batter's total bases accumulated in a game: 1B=1, 2B=2, 3B=3, HR=4. Common prop lines: 1.5, 2.5. Modeled with xwOBA, contact quality, and opposing pitcher EV allowed. Less variance than HR props — a smoother distribution to model.
- True Probability / Fair Odds
- The actual probability of an outcome, removing the sportsbook's vig. PropBetEdge's Poisson model generates its estimate of true probability. When true probability exceeds implied probability, the bet has positive expected value.
- Usage Rate (NBA)
- An estimate of the percentage of team plays a player is involved in while on the court. High USG% players have high floors in points/rebounds/assists props. Computed server-side in PropBetEdge's NBA boxscore endpoint.
- Variance
- The natural randomness in outcomes. A +EV bet loses most of the time if the implied probability is 30% — that's expected, not a sign the model is wrong. Over large sample sizes, variance regresses. Proper bankroll management survives the variance.
- Vig (Vigorish / Juice)
- See Overround. The sportsbook's commission. At −110 on both sides of a bet, you're paying about 4.7% to the house on each dollar risked. Shopping for the best odds reduces the vig you're fighting against.
- Whiff Rate
- See SwStr%. The rate at which a pitcher generates swinging strikes. Sometimes calculated differently — swings and misses divided by swings (vs. total pitches). Both measure the same thing: how often batters swing and miss.
- xBA (Expected Batting Average)
- A Statcast metric predicting how often a batter should get hits based on exit velocity and launch angle of contact, removing luck and defense. A better predictor of future BA than actual BA. Used in hits props modeling.
- xSLG (Expected Slugging Percentage)
- A Statcast metric predicting a batter's slugging percentage based purely on contact quality. The primary driver of HR probability in PropBetEdge's model. A batter with a high xSLG but low actual SLG is due for positive regression — and their HR odds may be underpriced.
- xwOBA (Expected Weighted On-Base Average)
- The most comprehensive Statcast offense metric — expected wOBA based purely on contact quality and pitch type, removing luck, defense, and ballpark. The best single-number predictor of true offensive talent. Heavily weighted in PropBetEdge's total bases and hits models.
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