Boston Red Sox' starting pitcher Matsuzaka looks down as he stands with catcher Martinez during their MLB American League baseball game against the New York Yankees at Yankee Stadium in New York

On May fourth I asked the question, Should Jason Varitek be the Starting Catcher?  Not much has changed as at the time I noted “In 146 IP thrown to Martinez the staff has a K/BB of 1.64, but when Varitek has caught in 83.6 innings the staff has thrown a 2.35 K/BB.”  That trend has largely continued as Varitek has saw more time, so how much is the difference worth?

Some things to keep in mind is that this is a skill we really can’t value before the catchers catch the same pitchers.  We knew Victor Martinez was not the best catcher, but how could anyone know for sure his pitch calling would raise these questions.  So this is more of an exercise done in retrospect and would help decide how to approach Martinez this offseason.

First we need to see how much better Martinez is by WAR (offense and defense, but not pitch calling).  Assuming Varitek regresses to his average for the past three years he is going to be worth between 0.5 and 1 WAR.  On the other hand Martinez as a starting catcher has to be expected to top 5 WAR and could be worth as much as 5.5.  Let’s look at the biggest split from 0.5 to 5.5 and give Martinez a 5 WAR or 50 run advantage on Varitek.

The numbers have leveled a bit compared to what we saw the first time I looked at these two, but still a split with pitchers throwing a 1.66 K/BB when Martinez is catching and a 2.10 when Vartiek is.  If we look at all the data from 2009 and 2010 the numbers are 1.77 and 2.46.

The big difference has been added strikeouts this year as Varitek has seen a K/9 from pitchers of 7.77, but Martinez has only a 6.61.  If we run the numbers threw a FIP evaluation with equal HR/9 of 0.98 (not accurate, but a simple evaluation using the team average) we would see a FIP of 4.48 when Martinez is catching and a 4.13 when Varitek is catching.  A separation of 0.35 runs so far this year per nine innings caught.

Trying to quantify that we need to see that Martinez has caught 295.1 IP so far this year and Varitek only 150.2.  That puts Martinez on pace for 1000 innings caught this year.  If he continues to be worth 0.35 runs against for every nine innings he will cost the team 39 runs or 3.9 wins.

There are some big qualifiers for this analysis.  The first is who they each caught.  If Varitek caught a larger number of games for Jon Lester his K/BB would be improved.  Looking at the 2009 data though I feel confident there is a significant split, but just a question of accuracy.  The other question is why the big difference?  Is Varitek calling a better game or does he position better to get better calls from the umpire.

The final breakdown is Martinez is still worth more to this team playing at least two-thirds of the games, but anymore than that it could be a larger problem.  With David Ortiz hitting again there is no room to move Martinez somewhere else and his bat is still something we can’t take out of the lineup.  His 5 WAR advantage is more than the 39 runs exchanged when catching, but something that should be viewed pitcher by pitcher for advantages.  Jon Lester seems to have no trouble with Martinez and would be a solid choice to throw to him consistently.