The Effects of the Opposite Field Strategy

Yesterday, I covered why Tony Bernazard’s strategy of emphasizing opposite field hitting is a bad idea. The report which broke the story mentioned that this strategy had surfaced at the MLB level. If so, we should be able to examine the profiles of Mets hitters and see if this strategy actually affected their production, and if so, if it was positive or negative.

However, when we deal with pull-push splits, we’re purposefully reducing the size of our data set, leading to the type of issues that we encounter with batter-pitcher splits, although not at quite the same magnitude. Toss in the issues that the Mets had with injuries, and it becomes even harder to establish solid conclusions. With only David Wright reaching the 600 PA mark, we will be dealing with both players without an established level of major league production as well as small sample sizes.

As mentioned yesterday, power, as measured by ISO, is much, much lower when the ball is hit to the opposite field. As such, one possible effect of this strategy would be a team-wide drop in ISO. Although the Mets team ISO did drop by about 20 points from 2008 to 2009, this can be almost entirely attributed to the loss of talent due to injury. We can still look at individual players. Here are David Wright, Fernando Tatis, and Carlos Beltran’s ISO numbers for their career.

Clearly, this trio had a power dip in 2009. This is consistent with the idea that power dips when more balls are hit to the opposite field. However, there are multiple factors at work here. Park factors are not accounted for, and Citi Field appears to play as a pitcher’s park. Beltran lost much of his year to injury and barely accrued 300 PAs. Tatis also did not reach 400 PAs, and also spent much of 2007 and 2008 in the minor leagues, meaning we don’t have full data as far as his trends go. We also miss the effects of aging.

The power dips for Beltran and Tatis are unsurprising given their respective ages of 32 and 34. Tatis actually pulled more pitches in 2009 than he did in 2008. Beltran had a lower pull rate as a LHB relative to 2008, but a similar one as a RHB. It doesn’t seem to be enough to definitively say that it affected his power significantly. Either way, given all the factors at work here, it is pretty easy to dismiss front office strategy as a reason for decline, at least with these two.

With Wright, it’s not so clear. He’s a young player a should have been entering his peak in 2009, and yet his ISO dropped off a cliff. In this case, we do indeed see a large difference in his splits. In 2009, he was nearly even in L/C/R hitting, whereas his pull rate was about 1.5 times his up-the-middle rate and 1.6 times his push rate in 2008. He did perform better according to wOBA on balls hit up the middle and to right field in 2009, but that seems to be entirely a function of high BABIPs, as there was still minimal power to be found in either split. It seems safe to claim that Wright did not pull as many pitches in 2009 and that this drop in pull rate is at least partially responsible for his drop in power.

A claim that we can’t make, however, is that the Mets strategy is to blame for Wright’s drop in power and productivity in 2009. Even though we see data that suggests a decreased pull rate resulted in less power, we don’t know that it was intentional or merely noise. If it was intentional, we don’t know if it was merely a change in approach brought about by a slump or if it was brought about by management. This doesn’t change the intelligence of the strategy – we just can’t make blanket statements about its effects on the 2009 Mets, due to the sample sizes and other mitigating factors at work.