Baseball Betting: Lefties vs. Righties

When it comes to handicapping baseball, nothing is more important than the pitching. If you don’t know that then you have some work to do. It’s not just who is pitching that day and how they have been playing, though. Different teams react very differently to right handed pitchers than they do to left handers. Over the first couple of weeks of the season those effects can be amplified and distorted by small sample sizes. A month into the season, though, teams are starting to have enough of a record that we can draw meaningful conclusions from what we have seen so far.

By understanding some of the teams with the biggest differences in performance depending upon which hand the pitcher is using you can identify some opportunities for profit, and avoid other costly mistakes.

The most glaring performance difference is with the Mets. In six games against left-handed starters they are averaging 8.17 runs per game. Against righties they have put up just 4.61 in 18 games. The production difference has impacted the win-loss records, too – they are an impressive 5-1 against the lefty starters and a less stellar 10-8 against the righties. With only six games against left handed pitchers it would be tempting to try to explain away the situation because they have faced lesser opponents, but that’s clearly not the case. The lefties they have faced have included Dontrelle Willis, Mark Redman, Cole Hamels and Jamie Moyer. That boost in performance is also reflected in the totals. They have gone over four times in the six games and pushed once. Against right-handers they have gone under 11 times in 16 opportunities That’s an opportunity regardless of who is pitching.

The Mets show, to an extreme, the opportunities that are available if you are observant. Their overall average of 5.5 runs per game is significantly higher than it should against right-handers and significantly lower than it should be against left-handers. If people are making betting decisions without breaking it down by side then there is a value opportunity available.

In the American League the most glaring difference is with the Cleveland Indians. They are averaging an impressive 6.2 runs per game in 15 tries against righties, but only 3.17 in six games versus left-handers. It’s not the case that they have hit left-handed aces playing at their best, either. They have gone against Johan Santana and Mark Buehrle, but neither of those aces were at their best, and they have also seen the struggling Kei Igawa. The difference in record is very glaring. They are 12-3 against right-handers, but just 2-4 against lefties – wildly profitable from one side becomes a money pit from the other side. The difference is reflected in the totals as well. They have gone under three ties and over twice against lefties, and over 10 times in 15 tries against right-handers. Again, profit opportunities have clearly been available here.

For some teams, it doesn’t seem to matter who is pitching. The Pirates’ offense is equally anemic from both sides – 3.5 runs per game in six against southpaws, and 3.61 in 18 against right-handers. Colorado (4.29 – 4.0), Kansas City (4.0 – 3.75), Washington (3.4 – 2.94) and the White Sox (4.0 – 4.18) also don’t seem to have a preference. It’s interesting to note that all five of those teams are struggling offensively. On the other hand, the Mets and the Indians are both playing well, and they have scored more runs than anyone in their league when facing their preferred pitcher. The opportunities from this kind of handicapping, then, would seem to be more plentiful the better the team is. That makes sense, since the impact of offensive changes are going to be more significant the more effective the offense is.

Overall, in the league the results are as you would expect. 22 of the 30 teams in the league have a better winning percentage when facing a pitcher that fits their preference. Some teams besides the Mets and the Indians have significant differences. Atlanta has scored 5.93 runs per games against right-handers, and their record is 12-3. The productions drops to 4.64 runs against left-handers, and the record also dips, to 5-6. Houston would be much more competitive if they never saw another left-hander. They are just 1-7 with 3.0 runs per game against them, but they are 9-7 with 4.69 runs per game when they avoid them. San Diego is 4-2 with 6.0 runs against lefties, and 9-11 and 3.85 against righties.

As with every rule there are exceptions. The Yankees, for example, have scored 0.86 more runs against left-handers, but they are just 2-4 in those games, and 7-10 in the rest of their games. That shows that nothing can operate in isolation – it doesn’t matter how many runs your team scores if your own pitchers can’t get people out.