MLB

Major League Baseball rolled out the Automated Ball-Strike (ABS) challenge system league-wide for the 2026 season. Home plate umpires still call balls and strikes, but the pitcher, catcher, or batter at the plate can challenge a call by tapping the top of their helmet. Challenges must be signalled within roughly two seconds of the call, and the player can’t look to the dugout for help. Each team starts with two challenges per game; a successful challenge isn’t deducted from that total. If a team still has a challenge but enters extra innings with none, they receive one additional challenge for the remainder of the game.

Between pitches, the clock runs for 15 seconds with the bases empty and 18 seconds with runners on base (reduced from 20 seconds starting in 2024) MLB.com. The pitcher must begin his delivery before the timer expires or the batter is awarded an automatic ball, and the batter must be set in the box by the 8-second mark or be charged an automatic strike. A 30-second timer runs between batters. Pitchers may step off the rubber or throw to a base twice per plate appearance without penalty — a third unsuccessful pickoff attempt awards the runner the next base.

Twelve teams reach the postseason — six from each league, made up of the three division winners plus three Wild Cards. The top two division winners in each league receive a first-round bye. The remaining four teams in each league play a best-of-three Wild Card Series, with all games hosted by the higher seed. Winners advance to the best-of-five Division Series against the top two seeds, then the best-of-seven League Championship Series, and finally the best-of-seven World Series. Home-field advantage in the World Series goes to the team with the better regular-season record.

MLB blackouts exist to protect the broadcast rights of regional sports networks (RSNs), who pay for the exclusive right to show local teams within a defined territory. If you’re inside a team’s designated home market — determined by your billing ZIP code or IP address — live games involving that team are blacked out on MLB.TV, even if you’re not a subscriber to the local RSN. The only legal routes around it are subscribing to the relevant RSN directly (where available), watching a nationally exclusive broadcast on Fox, ESPN, or TBS, or being physically outside the blackout territory. Archived games become available 90 minutes after the final out.

The luxury tax — officially the Competitive Balance Tax (CBT) — is MLB’s soft salary cap. Teams whose total payroll (calculated as the average annual value of all contracts, plus benefits and minor-league salaries) exceeds a league-set threshold pay a tax on every dollar over that line. Tax rates escalate based on how many consecutive years a club has exceeded the threshold and how far over it they are, with additional surcharge tiers at $20M, $40M, and $60M above the base. Repeat offenders above the top tier also face a drop of 10 spots in the following year’s draft. The thresholds step up each year under the current CBA.

In regular-season extra innings, each half-inning starts with a runner already on second base — commonly called the “ghost runner” or “Manfred man”. The runner is the player who made the final out of the previous inning (or a pinch-runner for him). Any run that scores because of this placed runner is charged to the pitcher as unearned, so it doesn’t affect their ERA. The rule, introduced during the pandemic-shortened 2020 season and made permanent in 2023, only applies to the regular season — postseason extra innings start with the bases empty, as traditionally. The goal is to shorten games and reduce bullpen strain.

The run line is baseball’s version of a point spread, and unlike football it’s almost always fixed at 1.5 runs. The favourite is listed at -1.5 (they must win by two or more runs to cover) and the underdog at +1.5 (they cover by winning outright or losing by exactly one run). Because roughly a third of MLB games are decided by a single run, the run line dramatically shifts the payout: backing a heavy moneyline favourite at -1.5 usually returns plus-money odds, while a +1.5 underdog typically comes at a price. Most sportsbooks also offer alternate run lines at ±2.5 for bigger swings in either direction.

An F5 bet — sometimes called a “first half” wager — settles on the score at the end of the fifth inning rather than at the end of the game. You can bet the F5 moneyline (which team leads after five), the F5 run line (usually set at 0.5 runs), or the F5 total (combined runs scored in the first five innings). The appeal is that it isolates the starting pitcher matchup and strips out bullpen variance, which is why sharper bettors often prefer it to the full-game line. One important quirk: unlike full-game moneylines, the F5 moneyline can push — if the score is tied after five, the bet is refunded. Books also offer a “first five with tie” three-way market at different odds if you’d rather lock in a result.

NRFI stands for “No Run First Inning” — a wager that neither team will score in the top or bottom of the first inning. The opposite market, YRFI (Yes Run First Inning), pays if either side puts at least one run on the board before the second inning starts. NRFI has become one of the most popular daily MLB props because it’s resolved inside 20–30 minutes of first pitch, turning a three-hour game into a quick-hit market. Sharp NRFI angles focus on the starting pitcher matchup, the top three batters in each lineup (not the full card), the home plate umpire’s zone, and park factors. Roughly 55–60% of MLB innings open scoreless league-wide, which is why sportsbooks typically price NRFI as the favourite.

It depends on which pitcher designation you chose when placing the bet. Moneyline and run line wagers default to listed pitchers at most US sportsbooks — if either announced starter is scratched before first pitch, the bet is voided and your stake refunded. If you selected action, the bet stands regardless of who starts, but the odds are recalculated at the book’s revised price. You can also split the designation: one listed, one action. Totals (over/unders) almost always default to action, meaning a pitcher change doesn’t void the bet. Player props on a specific pitcher are voided if that pitcher doesn’t take the mound. Rules vary slightly book-to-book, so it’s worth confirming before you place.

Weather is one of the most underrated handicapping variables, especially on totals. Wind is the single biggest factor: a 10+ mph wind blowing out to centre at Wrigley or Citi can add roughly 1–1.5 runs to the projected total, while the same wind blowing in suppresses scoring by a similar margin. Temperature matters because warm, humid air carries the ball further — a 90°F day typically plays around half a run higher than a 60°F one. Light rain affects ball grip for pitchers and can nudge walk and error rates upward, and heavy rain risks postponement that voids most bets. Indoor or roofed stadiums — Tampa, Toronto, Milwaukee, Arizona, Houston, Texas, Seattle and Miami — neutralise weather entirely.

The home plate umpire’s strike zone has a measurable effect on totals, strikeout props and walk props. League average is roughly 8.5 runs per game, but individual umpires range from about 7.8 (pitcher-friendly wide zones → more strikeouts, lower totals) to 9.2 (hitter-friendly tight zones → more walks, higher totals). Sharp bettors track each umpire’s rolling O/U record, K/9 and BB/9 over their most recent 50+ games behind the plate. Crew assignments are typically announced 30–60 minutes before first pitch, which narrows the window to act before the market adjusts. Most public bettors ignore umpire data entirely — which is precisely why it remains a profitable angle worth educating your audience on.