What is a runline.
The runline is baseball's spread, fixed at 1.5 runs. It trades a bigger price for a harder result — a win by two instead of a win by one.
The favorite lays −1.5. A −1.5 runline pays only if the favorite wins by two or more runs. If your team wins 3–2, the moneyline cashes but the −1.5 runline does not — the one-run margin is exactly what the runline is built to test.
The underdog takes +1.5. A +1.5 runline cashes if the underdog wins outright or loses by a single run. It is the mirror of the favorite side: more forgiving, so it pays less.
Runline versus moneyline. The moneyline only asks who wins. The runline asks by how much. Because the −1.5 side clears a higher bar, its price is longer — and pairing the two lets you take that longer price while hedging the one-run loss. That paired sizing is exactly what the runline calculator does.
Starting from a moneyline. If you are looking at a moneyline and want the runline instead, begin with the win probability the moneyline implies, then judge whether the matchup produces multi-run margins often enough to justify −1.5. The moneyline to runline converter shows that implied probability directly.
Runline questions
- Is the runline the same as the spread?
- Yes. The runline is baseball’s point spread, fixed at 1.5 runs. The favorite is −1.5 (must win by two or more) and the underdog is +1.5 (wins outright or loses by one).
- What does −1.5 mean on a runline?
- It means the favorite must win by two or more runs for the bet to cash. A one-run win loses the −1.5 runline even though the team won the game.
- When is the runline worth it?
- When the favorite tends to win comfortably and the runline price adds enough over the moneyline to pay for the two-run requirement. High-strikeout starters and lopsided bullpens push toward multi-run margins.