The three ways to bet a baseball game
Every MLB game offers the same three betting options, in slightly different flavors. Understanding the difference between them is the key to reading any line correctly.
Moneyline: who wins
The moneyline is the simplest bet: you pick the team you think wins, no matter the score. If you bet the favorite at -150 and they win 2–1, you win. If they lose, you lose. This is the market most beginners start with.
Runline: winning by 2 or more
The runline is baseball's version of a point spread. Most runlines are set at 1.5 runs. If you bet the favorite at -1.5, they must win by 2 or more. If you bet the underdog at +1.5, they can lose by 1 and you still win. The underdog runline is popular because the margin of loss doesn't matter as long as it's within 1.
Total: how many runs in total
The total is about the game length, not the winner. The book sets a number (say 8.5 runs) and you bet over or under. If the teams score 9+ runs combined, over wins; 8 or fewer, under wins. Rainouts, strong pitchers and big ballparks all affect this number.