Each sport also has certain phrases within betting them that only make sense to apply to them. The “run line” is one, as baseball is the only major sport that uses runs. This is the closest thing that a baseball game can have to a spread, and it is always set as -1.5 and +1.5 runs, given the limited scoring nature (in comparison to football and basketball). They do have alternate run lines up to -2.5 and -3.5 (as well as +2.5 and +3.5) but the lines on these are usually crazy and are rarely a smart bet.
MLB games have money line bets as well as totals, just like all other sports, but people like to bet the run line because there is less juice involved when betting on a team that is expected to win. When betting MLB games, there is usually a huge gap between the best team and the worst team in the league, but the cover percentage on the run line is way closer between the team that covers the most and the one that covers the least is only 19% apart (compared to 34% on regular win percentage).
Part of this is because each team had on average 44 one-run games played, which if they were favored on the run line but did not win by two or more runs, it still goes as a loss for the team on the run line. Also, the teams cover a lot more as an underdog on the run line, compared to as a favorite. Look at the New York Yankees for example, they were 52-82, or 38.8%, on the Run Line when favored, but 24-5, or 82.8%, on the run line when underdogs. These are good stats to look for positive regression on a team that underperformed, but this just shows how a team can be in a ton of one-run games, or have a bad year overall.
A crazy couple of stats are that the Los Angeles Dodgers were only underdogs three times last season, the Pittsburgh Pirates were only favorites thirteen times, and both teams only won one game in this scenario.
I expect the run lines to hit at an even lower rate in 2022 and beyond as they reverted the extra innings rules back from starting with a runner on second, which bailed out a lot of teams who could not get it done in regular time, only to start with a runner on second and create rallies with this pressure put on the pitching team.
Whether you’re new to sports betting or a betting pro, our Sports Betting Strategy and Advice page is for you. You can get started with our 101 section — including 10 Sports Betting Tips for Beginners — or head to more advanced strategy — like Key Numbers When Betting Against the Spread — to learn more.