MLB Run Line Picks

The run line is a 1.5-run spread, and unlike a football spread it almost never moves off that number — instead the price moves. That makes it a straightforward conversion problem: given the moneyline, what should -1.5 or +1.5 cost, and does the book's number beat it?

Because roughly a quarter of all baseball games are decided by exactly one run, the 1.5-run threshold sits on top of a large chunk of the outcome distribution, which is what gives the market its character.

Why One-Run Games Define The Market

About 28 to 30% of MLB games finish with a one-run margin, and roughly another 20% finish with a two-run margin. That distribution has two consequences.

Laying -1.5 means giving up every one-run win, which is a large fraction of the wins you would otherwise collect. In exchange the price improves substantially. Taking +1.5 means collecting every one-run loss, which converts a lot of losses into wins, and you pay heavily for it.

The market prices this conversion reasonably well on average, but the relationship between the moneyline and the run line price is not perfectly consistent across books or across price ranges, which is where the opportunity lives.

Approximate Conversions

Use these as a sanity check against what the book offers. If a -200 favourite's run line is available at +100 rather than the roughly -120 the conversion suggests, that is a genuinely better bet than the moneyline. If it is -145, the moneyline is the play.

When Laying -1.5 Is Correct

Three situations recur:

Heavy favourites at terrible prices. A -240 moneyline requires a 71% win rate to break even, and baseball favourites rarely justify that. The run line at a much shorter price is frequently the better expression of the same opinion.

A wide projected run gap. If your projection has one team scoring five and a half and the other three, you are not projecting a one-run game. Laying the runs matches the projection.

A high-variance favourite against a weak bullpen. Blowouts happen when a lead expands late against tired relievers. A favourite with a power-hitting lineup facing a depleted bullpen wins by multiple runs more often than its moneyline implies.

The counter-case: a favourite whose edge is entirely pitching-based, in a low-scoring park, against a team that puts the ball in play. Those games stay close even when the favourite wins, and -1.5 is the wrong instrument.

When Taking +1.5 Is Worth The Price

Less often, because the prices are brutal — a -450 +1.5 requires 82% to break even. But there are two legitimate cases.

The first is a dog in a low-scoring environment: a good pitching matchup, a suppressive park, and an opponent that does not hit home runs. Those games are close, and +1.5 collects the one-run losses that make up a large share of the dog's outcomes.

The second is a correlated structure rather than a standalone bet. A dog +1.5 paired with an under is a coherent view of a specific kind of game, and the correlation is genuine. Standalone, at -450, it is usually the worse half of the run-line market.

General principles about spreads and price conversion are covered in point spreads explained and implied probability.

Frequently Asked Questions