Baseball Betting Glossary: Every Term a UK Punter Needs from Action to Vig
Available in US
Baseball betting vocabulary comes almost entirely from the American market, and for UK punters raised on football terminology, the first encounter with “chalk,” “dime lines,” and “getting a hook” can feel like reading a foreign language. I spent my first season nodding along in forums while quietly searching every third term. This glossary is the reference I wish I had pinned to my wall from day one.
The US sports betting industry generated a record $16.96 billion in revenue in 2025, with baseball constituting a major share of that volume. The terminology that emerged from that market has become the global standard — understanding it is not optional if you want to follow analysis from American sources, which remain the richest pool of baseball betting insight available. Carsten Koerl, Sportradar’s CEO, has traced the growth of the US market from approximately $300 million in gross gaming revenue at the time of legalisation in 2018 to nearly $14 billion within a few years — and the language of that market travelled with the money.
A-F: Action, Chalk, Dime Line, and More
Action — A bet placed as “action” means it stands regardless of any pitching changes. If the listed starting pitcher is scratched before the game, your bet remains live. The opposite is a “listed pitcher” bet (see L section). I default to listed pitcher bets because the starter is the foundation of my analysis — remove him and the bet’s logic collapses.
Bankroll — The total amount of money you have dedicated to betting. Not your savings account, not your rent money — a separate, defined pot. Your unit size is calculated as a percentage of your bankroll.
Chalk — The favourite. “Taking the chalk” means betting the favoured team. In baseball, heavy chalk (a large favourite at -200 or steeper) often comes with poor value because the price reflects public confidence more than true probability.
Closing Line — The final odds offered at game time, just before first pitch. Sharp bettors measure themselves against the closing line — if you consistently get better prices than the closing line, you are likely making profitable selections regardless of short-term results.
Dime Line — A moneyline market where the difference between the favourite and underdog price is 10 cents (in American odds). For example, -130/+120 is a dime line. A 15-cent line would be -130/+115. Dime lines indicate lower bookmaker margin and better value for bettors. Baseball historically offered dime lines more often than other sports, though this has tightened at some operators.
Dog — Short for underdog. The team expected to lose, priced at plus-money odds. Baseball underdogs win more frequently than in most other sports, which makes the dog side a viable long-term strategy when properly qualified.
ERA — Earned Run Average. The average number of earned runs a pitcher allows per nine innings. The most commonly cited pitching stat, though advanced metrics like xFIP are more predictive for betting purposes.
First Five (F5) — A bet that settles based on the score after five innings. F5 bets isolate the starting pitching matchup and remove bullpen variance. Covered in detail in the first five innings betting guide.
G-M: Grand Salami, Hook, Juice, Listed Pitcher
Grand Salami — A bet on the total combined runs scored across all MLB games on a given day. If 15 games are scheduled, the Grand Salami total might be set at 112.5, and you bet over or under. It is a high-variance market that requires an opinion on the entire day’s slate rather than a single game.
Handle — The total amount of money wagered on a market or event. Not to be confused with revenue (the bookmaker’s profit). The MLB handle in the US alone exceeded $166 billion in 2025.
Hook — Half a point. “Getting a hook” means getting an extra half-run in your favour on a spread or total. If the run line moves from -1.5 to -1, you have gained a hook. In baseball, where many games are decided by one run, a hook on the run line or total is disproportionately valuable.
Juice — Synonymous with “vig” (see V section). The bookmaker’s commission built into the odds. A -110/-110 moneyline has 10 cents of juice on each side — you must risk 110 to win 100 regardless of which side you take.
Kelly Criterion — A mathematical formula for calculating optimal bet size based on your estimated edge and the odds offered. Useful as a reference but dangerous in its pure form because it assumes perfect knowledge of your edge.
Listed Pitcher — A bet condition where the wager is only valid if the specified starting pitcher actually starts the game. If the pitcher is scratched, the bet is voided and your stake returned. Most experienced bettors use listed pitcher conditions because the starting pitcher is the single most influential factor in game outcome.
Moneyline — A bet on which team will win the game outright, with no spread. The most common baseball bet type. Prices are expressed as positive (underdog) and negative (favourite) numbers in American format, or as decimal odds at UK bookmakers.
N-Z: Nickel Line, Push, Run Line, Totals, Vig
Nickel Line — A moneyline where the spread between favourite and underdog is 5 cents. For example, -115/+110. Even tighter than a dime line, a nickel line indicates extremely competitive pricing and minimal bookmaker margin. Rare in modern baseball markets but still found at some operators for certain matchups.
Over/Under — See “Totals.”
Parlay — An accumulator. Multiple selections combined into a single bet where all legs must win for the bet to pay out. Also called an “acca” in UK terminology.
Push — A tie against the spread or total, resulting in the stake being returned. If the total is set at 8 and exactly 8 runs are scored, the bet pushes. In run line bets, a push occurs if the margin of victory lands exactly on the line — though the standard -1.5/+1.5 run line eliminates push possibilities because you cannot win by half a run.
Reverse Line Movement (RLM) — When the betting line moves in the opposite direction from public money. If 70% of bets are on Team A but the line moves toward Team B, sharp money on Team B is moving the line against the public consensus. RLM is one of the most reliable indicators of sharp-side value.
Run Line — Baseball’s version of the point spread. The standard run line is -1.5 (favourite must win by 2+ runs) or +1.5 (underdog can lose by 1 run and still cover). Alternative run lines at -2.5 or +2.5 are available at some operators.
Steam Move — A sharp, sudden line movement caused by large bets from respected (sharp) bettors or syndicates. A steam move is one of the strongest signals that informed money has identified value on one side.
Totals — The over/under market for combined runs scored by both teams. If the total is set at 8.5, you bet whether the final combined score will be 9 or more (over) or 8 or fewer (under). Also called the “over/under” or just “the number.”
Unit — A standardised bet size, typically 1-3% of your bankroll. Using units rather than arbitrary stake amounts ensures consistent risk management across all bets.
Vig (Vigorish) — The bookmaker’s commission on a bet. Sometimes called “juice” or “margin.” The vig is the mathematical edge the bookmaker builds into every market. In a perfectly fair market with two equally likely outcomes, each side would be priced at 2.00 (even money). The vig reduces those payouts — typically to 1.91/1.91 — so that the bookmaker profits regardless of outcome.
WHIP — Walks plus Hits per Inning Pitched. A measure of how many baserunners a pitcher allows. A WHIP under 1.10 is excellent; above 1.40 is poor. Useful for assessing how much traffic a pitcher creates on the basepaths, which correlates with run-scoring risk.
Why do baseball betting terms differ from football betting terminology in the UK?
Baseball betting terminology originates from the US market, where the sport and its betting culture developed independently from European sports. Terms like ‘moneyline’ (match winner), ‘run line’ (handicap), and ‘juice’ (margin/vig) are American English equivalents of concepts UK bettors already understand under different names. As baseball betting in the US predates most UK sports betting culture, the American terms became the global standard for the sport.
What does ‘getting a hook’ mean in baseball betting?
‘Getting a hook’ means receiving an extra half-point in your favour on a spread or total. For example, if a total moves from 8.5 to 8, and you bet the under at 8.5, you ‘got a hook’ — the extra half-run means your bet pushes at 8 runs instead of losing. In baseball, where one-run games are common, a hook on the run line or total can meaningfully affect your long-term results.
Published by the Betting on Baseball Games team.
