Is Heath Bell Still A King Among Closers?

Since arriving in San Diego via Queens prior to the 2007 season, Heath Bell has put up Playstation-like (or should I say, Wii-esque) numbers. He ranks sixth among all relievers in Wins Above Replacement and leads the league in primal screams, bullpen sprints, pitching mound stolen bases and Elvis impersonations. The 34-year-old seemingly had another vintage season in 2011, rocking a 2.44 ERA and nailing down 43 saves. But look a little closer, and you might begin to wonder if there was a Bell impostor on the mound for the Padres this year.

Bell struck out a career-low 19.9 percent of the batters that he faced, below the 20.6 percent average for relief pitchers in 2011 and not even close to Heath’s 25.8 percent average entering the year. His strikeout rate (7.3 per nine innings pitched) was 2.2 punch outs per nine lower than his career average through 2010. With fewer Ks, Bell’s xFIP, an ERA estimator that evaluates a pitcher based on strikeouts, walks and an adjusted home run per fly ball rate, climbed to 3.67. That’s not much better than the 3.91 average for relievers.

What gives? What caused the pending free agent’s K rate to plummet? And can Bell continue making batters feel all shook up, or is he squarely in the late-1970s Elvis phase of his career?

Pitch selection could be factor. Pitch F/X data indicate that Bell threw a four-seam fastball averaging 93-94 mph about 70 percent of the time in both 2009 and 2010. In 2011, Bell’s Pitch F/X numbers show that he threw his four-seamer about 55 percent of the time and threw a sinker about 15 percent. That doesn’t appear to be a classification error, either. You can see that tossed a number of fastballs with more tail and sink (dark blue on the graph):

Sinkers tend to induce fewer misses than other types of fastballs, and that was the case with Bell. His sinker had a 7.3 percent whiff rate (whiffs out of total pitches thrown), compared to about eight percent for his four-seamer. That doesn’t sound like a huge difference, but it adds up when a pitcher is as fastball-centric as Bell.

There are other reasons for Bell’s K decline, however. The whiff rate on Heath’s bread and peanut butter and banana, his four-seamer, was between 9-10 percent from 2009-2010. And his curveball got a whiff a little more than 10 percent of the time in 2011, compared to 13-14 percent the previous two seasons.

It seems that when Bell went to put a batter away with a fastball or curve out of the strike zone, he couldn’t quite seal the deal. Bell didn’t exactly pound the zone, putting about 43 percent of his pitches in the strike zone (the average for relievers is 45 percent). While he did get a good number of swings on those outside pitches (31.7 percent, compared to the 30.8 percent average for RP), hitters made a lot of contact. Opponents put the bat on the ball 68.2 percent of the time that they offered at a pitch thrown off the plate, above the 65.3 percent average for relievers.

Courtesy of Joe Lefkowitz’s Pitch F/X Tool, check out Bell’s swinging strikes on out-of-zone pitches in 2010, compared to 2011:

2010

2011

Bell got fewer swings and misses on curveballs below the knees, and he also appeared to have less success climbing the ladder with his four-seamer.

Bell’s declining K rate, and the possibility that he’ll leave the pitching panacea known as Petco, is concerning. Wise owners will take note of those factors and look at Bell’s sub-2.50 ERA suspiciously. Changes in K’s per plate appearance become significant after 150 batters faced, and Bell took on 256 hitters this year. So odds are, his low-whiff 2011 isn’t just a fluke. Brian Cartwright’s Oliver projection system over at The Hardball Times has Bell striking out 8.4 batters per nine innings next year, with a 3.52 ERA.

Relievers just don’t toss enough innings for us to make sweeping conclusions based on one year’s worth of performance (neither do starters, for that matter), and Bell has been among the very best for a while. But Bell’s age, K decline and possible new home park should make you think twice before you drop a high pick. Bell’s not washed up, but his days as closer king could be over.