What's at stake

A single MLB game decides whether the St. Louis Cardinals or Pittsburgh Pirates wins outright and which side pays out on the moneyline.

Bets on the Pirates -1.5 and -2.5 run lines depend on margin of victory, while totals (6.5, 7.5, 8.5) settle on combined runs scored.

Who's in play

Starting pitchers and bullpens determine early scoring and late-game leverage, with individual pitch repertoires and recent workload shaping run expectancy.

Batting order construction, pinch-hitters, defensive alignments, and managers' willingness to use openers or lengthen starters affect whether a team covers a spread or pushes a total.

What drives it

Weather and the ballpark's hitting environment change run expectations, especially wind, temperature, and humidity that affect carry and fly-ball outcomes.

Lineup handedness, platoon advantages, recent team strikeout and home-run rates, and late-inning bullpen health are the main levers that shift moneyline, spread, and total probabilities.

What to watch

Probable pitchers announced about an hour before first pitch are the clearest signal for starting-matchup value and early-game run expectations.

Also watch announced lineups, first-inning weather reports, bullpen availability notes, early pitch counts, and live in-game odds swings during the first three innings.