The Derek Shelton Effect

As writers for a blog that claims to be home for progressive statistical analysis and reasoned argument, we try to stare a no-hitter in the face and say, "Thank you sir, may I have another?" By all accounts the Rays have had a very successful season and if anybody who frequents this site was given in April an option for the current standings scenario of the Rays, everyone would have signed right up. Having said that, Brandon Morrow's 17-strikeout one-hitter last weekend seemed to break through the soundproof booth protected by sample size causing many fans to scream, "Enough!" Jeremy Guthrie's combined three-hitter a few nights ago at the Trop puts the Rays squarely in the lead for games with three hits or less, an event that has occurred ten times year-to-date. It's been documented that the Rays are an all-or-nothing team this year, just as we were last season. Is it enough to simply leave it at that? Or has this year's offensive performance been worse under the guidance of new hitting coach Derek Shelton?

As a response to Morrow's outing there have already been two excellent columns on Shelton that everyone should read before or after you finish this. Shelton replaced Steve Henderson, largely with the mission to improve team situational hitting. Jason Collette at The Process Report breaks down this year's club versus last years and the league average in terms of hitting in various counts and base states in Grading Derek Shelton.  Shelton arrived this off-season with a GTMI (Get the Man In) mantra that has been beaten into our heads. Our own PGP uncovered that the Rays are indeed near tops in the league in terms of percentage of base-runners scored. Part of this is undoubtedly due to team speed and the ability to move yourself over without a ball in play, or take an extra base on a batted ball. Finally Transplanted took a macro-team look at factors such as walk rates and performance vs. pitch types for teams under Shelton.  Read all three and come to your own conclusion, but I didn't walk away with any clear takeaway.

There was one piece of the puzzle I thought still needed to be uncovered. Each year teams have player turnover. Read any season preview of the Rays and you will consistently find the expected regression of Jason Bartlett and Ben Zobrist's career year numbers being largely offset by positive regression from BJ Upton, Dioner Navarro, and Pat Burrell. Last year when Shelton replaced Henderson I penned a piece looking at how players performances fluctuated under Henderson concluding:

On his Twitter account Keith Law may have put it best when he described the firing as " ...Operation Fix BJ Upton".  The stakes with Upton are too high to not try every possible option, including a new hitting coach. While the above tables are not a clear indication of the need to replace Henderson, there is even less-to-no evidence to mandate keeping him.  The patterns are this: Old Rays have fared slightly better with new teams, new Rays have fared slightly worse, and current Rays have stayed nearly static. In the absence of any compelling argument to keep Henderson, two consecutive years of  -.030+ drops in wOBA from B.J. Upton is probably enough to warrant the change.

Let's take a similar look comparing current hitters performances using wOBA in 2009 under Henderson to 2010 working with Shelton.

Well that sure is ugly. BJ Upton is the only player to show real improvement year/year this season and even then Operation Fix BJ Upton surely had a loftier goal in sight than league average. Let's take one season outliers out of the equation and look at the 2010 projections of CHONE and Zips averaged together:

Ouch. Only Carl Crawford has exceeded his projection with a strong majority falling well short. An average under-performance of -.027 is close to applying the 10% pinch hitting penalty to an entire lineup of league average hitters or "The Shelton Effect. Finally lets look at the former Rays no longer on the 25-man roster, Navi and Pat the Bat.

Burrell, who has rebounded magnificently with the Giants somehow managed to fail harder this year while Navi was similar to 2009 while falling well short of projections. How have the Rays fared so well overall? The positive contributions of the Durham Bulls, namely Reid Brignac, Sean Rodriguez, John Jaso, and Dan Johnson have proven to be big upgrades over Navarro, Burrell, and Gabe Gross at the plate from 2009. That has gone a long way towards leveling out team year over year numbers, because individually the returning players are relatively floundering. Evaluating hitting and pitching coaches remains very difficult for team outsiders, but there has been so sign of improvement to date in the Shelton era. The Rays publicly seem very happy with Shelton as evidneced by this piece from the Sunday Times. One final caveat which dampens the impact of these results: the league average wOBA has declined seven points from 2009 from .336 to .329.