Like betting on other sports, there are different ways to bet the winner when placing bets on a baseball game. Betting the money line on a baseball game simply means picking the winner. Betting the run line on a baseball game is more like a spread bet in basketball or football. The run line in baseball is going to be standard at -1.5 or +1.5. Some books do offer alternate run lines like -2.5 or +2.5, but you will generally see -1.5 and +1.5. What does that mean? It means that the team must "cover the spread" by winning by that much or losing by less than the run line.
  • A team that has a -1.5-run line needs to win the game by two or more runs to win that bet.
  • A team that has a run line of +1.5 must lose by one run or win the game in order to win that bet.

Betting Favorites on Run Lines

Run lines are popular bets because some people don't like to lay the odds on a big favorite. A team may be a favorite of -200, but the run line will be -1.5 at plus money, like +140 or +150. Some people don't like to bet $200 to win $100, but they will gladly bet a favorite at -1.5 +150 so that they can bet $100 to win $150. The thought process behind favorite run line betting is that the team is expected to win anyway, so why not bet that team to win by two or more runs? More often than not, big favorites are popular run line bets because there is already that built-in expectation that they will win. That is half the battle right there. A -1.5 favorite on the run line has to win the game. Then they have to win the game by at least two runs.

Betting Underdogs on the Run Line Strategy

The best strategy for betting +1.5 lines is to take big underdogs in that role. Maybe a bad team has a good pitcher on the mound.
For example, consider the 2018 San Francisco Giants. Madison Bumgarner is still a very good pitcher, but his team was not very good. Maybe the Giants were facing Clayton Kershaw and the Dodgers and the line was Giants +225 and Dodgers -250. A +225 underdog faces long odds to win the game, but losing a one-run game is not out of the realm of possibility. Instead of gambling on a long shot, some bettors will give themselves the safety net of the +1.5 in hopes that the Giants lose the game by only one run or find a way to win. The vig is a lot different on a +1.5, but there are a lot of one-run games in MLB.
Most people that bet run lines are going to bet -1.5 run lines because of the plus money return on a big favorite. Maybe a bettor believes that a team that is just a -115 favorite should have a bigger edge. At that point, the bettor can take that team -1.5 and turn that into a big return of something more like $100 to win $200 instead of $115 to win $100.

Final Thoughts on Betting MLB Run Lines

One downside to this type of bet is that the team might win the game but lose the run line. Another downside is that the underdog may have won at +200 but using the run line cut into your profit potential. The run line is baseball's version of a spread bet and should be approached with caution, but it can be a profitable baseball betting option in certain situations.