Varitek’s Value

Scott Boras is known for his ridiculous assertions in an effort to boost his client’s worth on the free agent market. We’ve already talked about his hilarious Oliver Perez as Sandy Koufax argument, so today, we’ll look at his claims that Jason Varitek’s defense is so valuable behind the plate that he’s worth “Posada money”, or about $13 million a year.

The heart of Boras’ claim is that Varitek has a significant, positive influence on Boston pitchers, far more so than any other catcher, and this influence directly translates to wins on the field. He presents the ’08 Red Sox .608 Winning Percentage with Varitek behind the plate versus just a .524 Winning Percentage when he didn’t start as evidence. It doesn’t just stop there, however – if you look at the pitching performances in those respective games, there’s a massive difference.

In games where Varitek started behind the plate, the Red Sox pitching staff had a 3.94 FIP. In games where anyone else started behind the plate, the Red Sox pitching staff had a 4.80 FIP. That’s a pretty striking difference, and FIP is obviously a better measure of the team’s pitching than winning percentage. So, is Boras on to something in regards to ‘Tek?

Maybe, but the macro view of the two statistics just presented don’t help us find out. There’s all kinds of problems with using the data just presented as evidence that Varitek helps his pitchers, starting with the fact that games started by Varitek isn’t a representative random sample. He caught all of Josh Beckett’s 27 starts, 30 of 33 Jon Lester starts, and 27 of 29 Daisuke Matszaka starts. Of the 89 starts made by the Red Sox top three starters, Varitek caught 84 of them. Of the 73 starts made by the various #4 and #5 starters that Boston cycled through, Varitek only caught 36 of those.

If the Red Sox hadn’t performed better with ‘Tek behind the plate, it would have been a massive upset. When 70% of your starts come with one of the big three on the mound, it’s a virtual lock that the team will have a lower ERA with you behind the plate than when you’re not, simply due to the talent level of the pitchers that you’re catching.

So, instead of looking at the macro approach, let’s look at how each individual pitcher fared when ‘Tek was catching compared to when Kevin Cash was behind the plate. There were some huge dropoffs among some pitchers when Varitek wasn’t catching.

David Aardsma: 3.33 FIP w/Tek, 6.71 FIP w/Cash
Hideki Okajima: 3.13 FIP w/Tek, 6.06 FIP w/Cash
Julian Tavarez: 3.06 FIP w/Tek, 5.62 FIP w/Cash
Craig Hansen: 3.76 FIP w/Tek, 6.08 FIP w/Cash
Jon Lester: 3.64 FIP w/Tek, 4.60 FIP w/Cash

On the other side of the coin, the swings weren’t as large, but perhaps more interesting.

Mike Timlin: 6.37 FIP w/Tek, 3.48 FIP w/Cash
Bartolo Colon: 4.54 FIP w/Tek, 3.37 FIP w/Cash
Clay Buchholz: 4.86 FIP w/Tek, 3.90 FIP w/Cash
Daisuke Matsuzaka: 4.12 FIP w/Tek, 3.80 FIP w/Cash

Three starting pitchers did better with Cash than with Varitek, while only one did better with Varitek than Cash. If Varitek really was significantly better at calling pitches and helping his pitchers improve, wouldn’t that be manifest most strongly with the guys he prepares with ahead of time, rather than the ones that come into a game without much notice?

Still, though, the sum difference of the FIP by the pitchers that Varitek and Cash had in common was +.252 when Varitek was behind the plate. That’s a huge difference, worth about 28 runs over a full 1000 inning catcher season. If we could actually prove causation, and not just correlation, Boras’ argument for Varitek wouldn’t be all that crazy after all.

Unfortunately, we just can’t. We just don’t have precise enough tools to judge whether the performance fluctuation can be credited to Varitek, or if it was just random variation. So, while there is some evidence that the Red Sox pitchers did quite a bit better when he was behind the plate, we just can’t say with any kind of certainty that it’s a sustainable skill that will go with him wherever he plays in 2009.

Buyer beware – if you pay a significant amount of money for Jason Varitek’s catching skills, hoping that your pitching staff will magically improve, you’re betting on a hope.