Run Line
The run line is MLB’s version of a point spread. Unlike football and basketball spreads (which vary by matchup), the run line is almost always set at exactly 1.5 runs, with odds adjusted to reflect each team’s chance of covering.
How It Works
A standard MLB matchup looks like this:
| Bet Type | Yankees | Red Sox |
|---|---|---|
| Moneyline | -160 | +140 |
| Run Line | -1.5 (+135) | +1.5 (-155) |
If you bet the Yankees -1.5 (+135), you need them to win by 2 or more runs. A 7-2 Yankees win covers; a 7-6 Yankees win does not (the run line loses, even though the moneyline wins).
If you bet the Red Sox +1.5 (-155), you win if the Red Sox win outright OR lose by exactly 1 run. A 7-6 Red Sox loss covers; a 7-2 loss does not.
The half-run prevents pushes — every game produces an outcome on the run line.
Why It Matters
The run line creates a meaningfully different bet than the moneyline:
For underdogs: Taking the +1.5 transforms a moneyline underdog into something close to even-money. Backing a +140 underdog moneyline becomes -155 on the run line — a much higher win rate, smaller payout per win.
For favorites: Taking -1.5 transforms a heavy moneyline favorite into a profitable-payout bet. A -200 moneyline favorite might be +140 on the run line. The trade-off: requires a 2-run win instead of any-margin win.
Because MLB games are often tight, run line outcomes can diverge significantly from moneyline outcomes. Roughly 30% of MLB games are decided by exactly 1 run, which means roughly 30% of the time the moneyline winner doesn’t cover the -1.5 run line.
This creates middling opportunities specific to baseball: a moneyline bet on the favorite combined with a run-line bet on the underdog can produce double-win outcomes when the underdog loses by exactly 1.
For more on how spreads work across sports, see Moneylines, Spreads, and Totals.