Twice in the last week I was asked if the concussion that David Wright received on August 15, 2009 from a Matt Cain fastball was the cause of his recent drop in production. I decided see what if anything has changed in David Wright from before getting hit in the head and after.
First, here are the career numbers for David before and after the concussion:
David as had close to a 50 point drop off in his batting average from the time before the concussion to after it. His OBP and SLG have also experienced about 50 points drops. One possible cause of the drop off in production could have been the change in home stadiums for the Mets. In 2008 and earlier, the Mets played in Shea Stadium, but since then they have been in Citi Field. The actual stadiums have played similar, which is hitter and pitcher neutral. Here are the wOBA for both of the stadiums for in 2008 (Shea) and 2009 (Citi).
Shea Stadium wOBA (LHB/RHB): 101 /99
Citi Field wOBA (LHB/RHB): 99/100
(less than 100 is pitcher friendly, over 100 is hitter friendly)
Moving to Citi field should have given David a small boost in his offense output which has not occured.
Another obvious factor is the effects from the concussion. The season that the concussion occurs, there is to be some effect to a player’s ability to hit. The season after a player has received an concussion, they no longer see any effects from the concussion (comment #24).
Not all of the drop off in production can be explained by the “normal” effects seen from a concussion. Two main factors seem to be driving the decline in David’s production which are an increase in K% and FB%.
David’s strikeout numbers have gone from 21.4% before the concussion to 29.1% after the concussion. Looking at his plate discipline numbers, all values are the same before the concussion and after excect his strike zone contact numbers which have gone down from ~90% to less than 85%.
To further show the change, here are images of all the pitches he swung and missed at in 2008 and 2010.
As it can be seen, he is now missing more balls that are inside and middle -or- low and down the middle of the plate.
Besides the increase in strikeout rate, David is hitting more fly balls in the past couple years than in the previous seasons. David’s line drive rate is down about 5% while his OFFB% is up about 5%. He seems to be not hitting line drives, which more often go for hits. Instead he is opting for fly balls which usually end up as outs, but occasionally turn into home runs.
Looking back the park factors for Citi vs Shea, even though they both have even wOBA, Citi’s home run park factor were in 90/94 (LHH/RHH) in 2009 while Shea had home run park factors of 114/106 (LHH/RHH) the season before.
In my opinion, David Wright changed his approach between 2009 and 2010 when he moved into Citi Field to try to keep his home run numbers up. In the process he is missing a few more pitches in the zone leading to an increase in strikeouts. Since he is looking for more home runs, he is hitting more fly balls instead of line drives which generally lead to more production.
I don’t believe that the concussion that David got in 2009 affected his ability to hit the ball. I think it was just a coincidence that it occurred during the same year he was adjusting to spacious Citi Field. If David had maintained the similar approach he had at Shea, he could have been just as productive (similar wOBA). Instead, he attempted to maintain his home run output and the rest of his offensive game has suffered.
Thanks to statcorner.com for the park factors and www.joelefkowitz.com for the Pitch FX data