“Lights Out” Returns (But Did He Ever Leave?)

It’s once again time to play one of our favorite games around these parts: Name That Pitcher! Here are our mystery hurlers…

Pitcher A: 69.1 IP, 11.94 K/9, 4.54 BB/9, .317 BABIP, 82.9 LOB%

Pitcher B: 67 IP, 11.82 K/9, 4.03 BB/9, .308 BABIP, 78.3 LOB%

As you can see, our mystery pitchers are strikingly similar. Both racked up huge strikeout numbers and walked a fair amount of batters. Neither guy experienced terrible luck on balls in play, though Pitcher A fared worse in that category. Pitcher A was also a little better in stranding runners on base. Overall, though, these two stat lines are near reflections of one another.

However, the perception of the two diverges pretty dramatically. Pitcher A was a perfect 41-for-41 in save opportunities and was considered to have perhaps the best relief season in the game. On the other hand, Pitcher B was considered a pretty large disappointment, so much so that he was shipped out of town for a middle reliever, a lukewarm third base prospect and a center fielder who posted a mind-numbing .276 wOBA (22.1 runs below average) in 2008.

So, who are these guys? As you’ve probably already guessed, Pitcher A is Brad Lidge. Pitcher B is…also Brad Lidge, in 2007.

While Lidge was somewhat better in 2008, this comparison serves to show how there really wasn’t that wide of a difference between “head case” Lidge in ’07 and “World Series champ” Lidge in ’08. Using Expected Fielding Independent ERA (XFIP) from The Hardball Times (which evaluates pitchers based on strikeouts, walks and a normalized home run/flyball rate), we find that ’07 Lidge (3.42) was a little worse than ’08 Lidge (3.06), but not by as much as one might initially think. What led to the big gap in perception?

Home runs. In 2007, Lidge gave up 9 long balls in 67 innings, or 1.21 per nine innings. His Home/Flyball rate was pretty lofty, at 13.2% (and that was actually an improvement from an inauspicious 16.4% mark in ’06). In 2008, Lidge served up only 2 home runs in 69.1 innings, or a measly 0.26 per nine innings.

Nothing changed dramatically in the Notre Dame product’s batted ball data- rather, his HR/FB rate sank to an absurdly low 3.9%. To put that into context, pitchers typically give up two and a half to three times as many homers per flyball hit, and Lidge’s career HR/FB is 10%. Couple regression to the mean with a homer happy ballpark (Citizens Bank’s three-year HR park factor is 122), and it seems very likely that Lidge’s HR rate will quadruple next season.

This is the challenge faced when evaluating reliever performance. We’re dealing with inherently small sample sizes, and a few fortunate or unlucky bounces here or there can dramatically change the perception and quality of a player’s season. By most measures, Brad Lidge circa 2007 was a doppelganger of the relief ace that helped the Phillies win a world championship. But because a few extra flyballs found their way into the stands in ’07 and virtually none did in ’08, the two seasons are viewed as different as night and day.

The purpose of this exercise is not to diminish Brad Lidge’s accomplishments this past season. He enjoyed an excellent ’08 campaign, racking up a league-leading 5.37 WPA. However, his minuscule HR/FB rate does figure to rise in 2009. With some extra souvenirs likely finding their way to the paying customers, Lidge might revert back to the 2007 version of himself next season. And you know what? That’s not really a bad thing.