What's at stake

Game result, margin, and scoring totals determine the market outcomes.

Bets resolve on moneyline (winner), run line (1.5-run margin), and several over/under totals from 2.5 to 9.5 runs; payouts depend on posted lines.

Who's in play

Starting pitchers set the tone, but bullpens and sluggers often decide late innings.

Managers' lineup choices, the health and recent workload of each club's relievers, and which hitters are available determine whether marginal at-bats produce runs or outs.

What drives it

Pitching matchups, park factors, and weather shape baseline run expectations before the first pitch.

Live signals — announced starters' splits, wind direction and speed, umpire strikezone tendencies, and recent team strikeout or walk rates — are the causal levers that move totals and spread odds.

What to watch

Probable pitchers and official lineups are usually posted roughly an hour before first pitch; pregame injury updates can flip expectations.

During the game monitor early-inning run scoring, bullpen usage, pitch counts, and wind changes; key manager moves and ejections also change run probabilities quickly.