I took a walk through the stats last year and came to the same conclusion. For those that don't want to read all that the basic thought process was that in 2010 his K-rate went way up and his BB-rate went down. While this could have been because of the "D-back Way" the numbers seemed to to be backed up by other fancy stats, most notably a increase in his swings at pitches out of the strike zone, a decrease in contact at pitches in the strike zone and an drop in his line drive rate.
Look at what happened last year to those stats:
- K-rate back down from 28.0% to 20.9%
- BB-rate back up from 7.8% to 14.1%
- Swinging out of the strike zone down from 28.1% to 21.8%
- Contact in the strike zone up from 85.1% to 87.4%
- LD% up from 18.2% to 19.1%
In other words, everything I was looking at got better. In fact they basically returned to what he was doing the few years prior to 2010. The exception was the LD% which didn't quite get there - but his... let's say "post-contact" stats were all messed up - he was basically grounding everything weakly - we assume that's the injury...right? So back to the question at hand - maybe it was the the D-backs? To check that I looked at the players who joined Arizona in 2010 from other teams to see how they fared compared to the 2-3 years prior
K-rate - Up
BB-rate - Up
Swing Out - Up (but not by much)
Contact In - Down
LD% - Up
Tony Abreu (I could only find minor league stats for K-rate and BB-rate. His major league AB are really limited)
K-rate - Up
BB-rate - Down
Mostly got worse. What about those that left the D-backs in 2011 in comparison to 2010?
Swing Out - Up
Contact In -UpLD% -No Change
Swing Out - Down
Contact In -Up
LD% - Up
Mostly got better. Toss in LaRoche's numbers here and you do see a small (and to be honest, totally unconclusive, it's five players we're talking about here) pattern. The 2010 Diamondbacks, who not only led the league in K's but set an all-time record in the stat, may have adversely affected their hitters with the approach the team took to at bats. I'm not saying they struck out too much (I don't really believe that matters), but there is a difference between "Find a good pitch, swing from the heels, we don't care if you whiff" and "Swing from the heels, we don't care if you whiff". The D-backs may have strayed too much toward the latter and suffered because of it.
What does this mean for LaRoche? Well maybe I was too harsh in the initial judgement. If it was the "D-back Way" that caused a drop in stats in 2010, not the inevitable decline that comes with age, than perhaps there's a good chance a healthly LaRoche can put up that .275 60 BB 25 HR season the Nats were hoping for when he signed. That may not seem like much but it would be an improvement over what LF was producing last year and this offense needs to find improvements.