why do Left handed hitters have more extreme splits?

[dominik]

I was watching the splits in the 2012 season and noticed that lefties have more extreme splits (OPS).

http://www.baseball-reference.com/leagues/split.cgi?t=b&lg=MLB&year=2012

LHH vs RHP .748
LHH vs LHP .648

RHH vs RHP .704
RHH vs LHP .754

so the difference is 100 points for lefties and only 50 for righties. what is the reason?

[BigRon]

It's really pretty simple. Almost all batters see the ball a little bit better when facing a pitcher from the opposite side- that is, a right handed batter against a lefthanded pitcher and a left handed batter against a right handed pitcher. So, lefthanded batters in 2012 had OPS of .748 against RHP and righthanded batters .754 against LHP- almost identical.

At the same time, batters almost always do better when they see something frequently- more at bats against a pitcher in the same game, for example. The same is true when they hit more against "same side" pitchers. Righthanded batters see righthanded pitchers at least 70% of the time- maybe a little more- so they get accustomed to seeing the "same side pitches- and don't do too much worse against RHP- .704 vs .754. But, lefthanded batters only bat against LHP 25- 30% of the time, and don't get enough experience with "same side" pitches to adjust as well. Therefore, .648 vs .748.

If the situation were reversed- if about 70- 75% of pitchers were lefthanded and only 25- 30% righthanded, the results would be reversed.

[dominik]

that is a good arguement but RHB see LHH only like 25% too and still the hit them as well as LHH do hit RHP despite a lot more experience.

another reason might be selection as a RHB is not likely to make the majors at all if he can't hit RHP (because they are 2/3rd of all pitchers and it would be bad to suck against most pitchers while there are even some very good LHH who cannot hit LHP).

[BigRon]

that is a good arguement but RHB see LHH only like 25% too and still the hit them as well as LHH do hit RHP despite a lot more experience.

another reason might be selection as a RHB is not likely to make the majors at all if he can't hit RHP (because they are 2/3rd of all pitchers and it would be bad to suck against most pitchers while there are even some very good LHH who cannot hit LHP).

I can't prove it statistically but I think there is a threshhold effect. Hitting opposite side pitching is less difficult than hitting same side pitching. That much is clear. I think that it isn't necessary for many RHB to face a very high percentage of LHP to do well. Perhaps the 25- 30% range is beyond the threshhold, and performance becomes "flatter" at that point.

Other than that I really do not believe there is any inherent difference between lefthanded and righthanded batters, except for lefthanders' advantage in being at least one step closer to first base when hitting.

[drstrangelove]

another reason might be selection as a RHB is not likely to make the majors at all if he can't hit RHP (because they are 2/3rd of all pitchers and it would be bad to suck against most pitchers while there are even some very good LHH who cannot hit LHP).

This is the answer IMO.