MLB Betting Glossary for UK Punters: 40 Terms Explained in Plain English
Available in US
The first time I sat down with a new UK punter trying to make sense of an MLB betting screen, we spent fifteen minutes just on the terminology. “Moneyline” is not a term British football bettors grow up with. “Vig,” “juice,” “action,” “no action,” “push” — these words mean specific things in MLB betting that have no direct equivalent in how UK sports betting language developed. This glossary covers the forty terms you are most likely to encounter, defined in plain English with no fluff.
Core Market Terms
Moneyline: The bet on which team wins the game outright. No spread, no handicap. In UK bookmaker interfaces, this is often labelled “Match Result” or “Match Winner,” which is the domestic football equivalent. At most UK operators, moneyline odds are presented in decimal format: 2.10 means a £10 bet returns £21 total.
Run Line: Baseball’s version of a point spread. The standard run line is set at -1.5 for the favourite and +1.5 for the underdog. If you back the favourite at -1.5, they must win by two or more runs. If you back the underdog at +1.5, they can lose by one run and you still win. UK bookmakers sometimes label this “Handicap Betting” or “Asian Handicap (Baseball).”
Over/Under (O/U): A bet on the combined total runs scored by both teams. The bookmaker sets a line (e.g., 8.5); you bet on whether the actual total will be higher (over) or lower (under). Also called “Totals” or “Total Runs” in UK interfaces.
First 5 Innings (F5): A market restricted to the first five innings of the game. Available as a match result (who leads after five) or as a totals market (combined runs in the first five). Settles once five innings are complete. Extra innings are irrelevant.
Run Line Spread: The numerical handicap applied to a run line bet. In MLB, this is almost always -1.5/+1.5. Unlike basketball or American football, the spread almost never moves away from this fixed number — the juice (see below) adjusts instead.
Alternate Run Line: A modified run line at a different spread, such as -2.5/+2.5. These offer different odds to the standard -1.5/+1.5 and are available at select UK operators. Used by bettors who want a larger payoff on a heavy favourite or reduced exposure on an underdog.
Grand Salami: A single over/under line on the total combined runs scored across all MLB games played on a given day. One of the most entertaining and volatile markets in baseball. Voids if any game on the day’s slate is postponed.
Series Bet: A bet on which team wins a scheduled series of games (typically three games in regular season). Separate from individual game bets. Settlement depends on the results of the games actually played within the series window.
Outright / Futures: A bet on a long-term outcome, such as which team wins the World Series, a division title, or an award like the Cy Young. Also called “Ante-Post” at some UK operators. Settlement can be months away from when the bet is placed.
Same-Game Parlay (SGP): A single bet combining multiple outcomes from the same game (e.g., Team A to win + Player X to hit a home run + Over 8.5 runs). UK operators call this “Bet Builder” on their platforms. More restrictive correlation rules than standard accumulators.
Void and Settlement Terms
Void / No Action: A bet that is cancelled and the stake returned. In MLB, voids typically occur due to postponements, suspended games that did not become official, player non-participation (for props), or pitcher changes under listed pitcher rules. “No action” is the American equivalent of “void.”
Official Game: The threshold at which an MLB game’s result is considered final for betting purposes. Standard threshold: 4.5 innings (five full innings if the home team is winning). Games called before this threshold result in voided bets.
Suspended Game: A game halted mid-play and not immediately resumed. If suspended before reaching official game status, bets void. If suspended after becoming official, the result stands at the point of suspension.
Push: An outcome where the total lands exactly on the line (e.g., a total of exactly 8.0 when the line is 8). Stakes are returned. MLB bookmakers typically avoid whole-number lines to prevent pushes, but it can happen on half-point alternate lines.
Postponed: A game that is officially deferred to a future date before it begins. All bets on a postponed game are voided. Contrast with “suspended” (game started but halted).
Settlement: The process by which a bookmaker calculates and pays out (or collects) on a resolved bet. Automated for most MLB markets, typically within 30-60 minutes of the final result being confirmed.
Action (as a bet condition) — The bet will stand regardless of pitcher changes. The opposite of “listed pitcher.” Since 2024, most UK operators use action as the default condition for MLB bets.
Dead Heat: When two or more outcomes finish jointly in a market with a single declared winner (common in award betting and outright markets). UK operators apply dead heat rules: each winner’s payout is divided by the number of joint winners.
Pitcher and Game Terms
Listed Pitcher: The starting pitcher named in the market at the time the bet was placed. Under “listed pitcher” rules, if that pitcher does not start, the bet voids. Becoming rare at UK operators post-2024.
Scratched: A player or pitcher removed from the starting lineup after originally being listed. A scratch late in the day — sometimes announced only hours before first pitch — is the most common trigger for pitcher-related void scenarios.
Bullpen Game: A game where a team uses multiple relief pitchers from the first inning rather than a traditional starting pitcher. Typically announced when a team wants to rest their rotation or has no available starter.
Doubleheader: Two games played between the same teams on the same day. Traditional doubleheaders use seven-inning games. Games are labelled Game 1 and Game 2 by UK operators.
Rain Delay: A halt in play due to weather conditions. Short delays do not affect bets. Extended delays that lead to a game being called before becoming official will void most bets.
Walk-Off: A game-ending play in which the home team scores the winning run in the bottom of the final inning, ending the game immediately. Walk-offs can happen in regulation or extra innings.
Ghost Runner: The automatic runner placed on second base at the start of each extra inning under current MLB rules (introduced 2020). Runs scored by the ghost runner count in all over/under markets.
Odds and Value Terms
Decimal Odds: The format used by UK bookmakers to display payouts. A decimal of 2.50 means a £10 bet returns £25 total (£15 profit). To convert from American moneyline odds: positive American odds (+150) = (150/100) + 1 = 2.50 decimal. Negative American odds (-130) = (100/130) + 1 = 1.77 decimal.
Vig / Juice: The bookmaker’s margin, built into the odds. If true odds on a coin flip are 2.00/2.00, a bookmaker offering 1.90/1.90 on both sides is taking vig. In MLB moneyline markets, the vig is often expressed as the difference between a true probability and the offered price. More detail on this is in the guide to MLB moneyline betting for UK punters.
Line / Price: The odds or spread set by a bookmaker on a market. The line moves as money comes in on one side, bets are placed, and new information arrives (injuries, weather, lineup changes).
Value: A bet where you believe the true probability of an outcome is higher than what the bookmaker’s odds imply. A team with true 55% chance to win offered at decimal 2.00 (50% implied probability) represents value.
Opening Line: The first odds published by a bookmaker on a game, typically the evening before. The opening line reflects the market’s initial assessment before public and sharp money influences the price.
Closing Line: The final odds before a game starts. Sharp bettors (professional, high-volume bettors) move lines toward the true probability over time; a bet placed at better-than-closing odds is generally considered evidence of value-seeking.
Two-Way Market: A market with only two possible outcomes (win/win), as opposed to three-way markets in football (home/draw/away). MLB moneyline is two-way, which affects how the vig is constructed.
Cash Out: The ability to settle a bet before its natural conclusion at a value offered by the bookmaker in real time. Available on most MLB markets at UK operators, with values updating after each half-inning in live markets.
Accumulator (Acca): A single bet combining multiple selections, where all must win for a payout. Each selection’s odds are multiplied together. An MLB four-team accumulator requires all four teams to win on the same day.
Bet Builder: UK operator branding for same-game parlay products. A Bet Builder combines multiple outcomes from a single game into one bet. Subject to correlation restrictions that differ between operators.
Spread Betting: Not to be confused with run line betting. Financial spread betting on sports outcomes is a separate product offered by specialist providers, where payout is based on the margin of victory rather than a fixed outcome. Standard MLB run line bets are not spread bets in this sense.
Glossary FAQs
What is the difference between ‘no action’ and ‘void’ in MLB betting?
They mean the same thing — the bet is cancelled and your stake is returned. ‘No action’ is American terminology; ‘void’ is the UK standard term. Both indicate that the bet could not be settled due to a qualifying event (postponement, pitcher scratch under listed rules, player non-participation in a prop). If your UK operator shows a bet as ‘no action,’ expect your stake to be refunded exactly as it would be for a void.
What does ‘juice’ or ‘vig’ mean and how does it affect my payout?
Vig (short for vigorish) is the bookmaker’s built-in margin. In a fair market, both sides of a two-outcome bet would pay 2.00. In practice, UK bookmakers might offer 1.90 on each side — meaning the implied probabilities add up to more than 100%, and the difference is the operator’s margin. Over time, betting at -5% margin (vig) rather than 0% has a significant compounding effect on your returns. Finding markets where the vig is lower — or where you believe the offered odds underestimate the true probability — is the basic premise of value betting.
What is the difference between ‘moneyline’ and ‘match result’ at UK bookmakers?
They are the same product with different names. ‘Match result’ is UK domestic sports language (from football); ‘moneyline’ is US sports betting language. UK operators often display both terms — ‘moneyline’ in their baseball sections to match how US-literate punters think about the market, and ‘match result’ in their general sports templates. When you see either term on an MLB betting slip, you are backing one team to win the game outright with no spread conditions.
Created by the ”mlb Betting Rules” editorial team.
