...And you'd never guess it from how they are received by Phillies fans.
While Stutes is almost universally beloved (he already has his own "UUUUUUUUUUUU" chant), Herndon is almost universally reviled. While most Phillies fans feel confident with Mike Stutes appearing in high-leverage situations, they would be utterly apoplectic if Herndon was used in the same situations as often as Stutes is. To a certain extent this is understandable. Fans tend to value results more than process, and Stutes's 3.18 ERA would suggest that he is a whole lot better than Herndon, whose ERA sits at 4.46.
But here we value process, and if we look at the things that are under each pitcher's control, we quickly realize the extent to which perception is out of line with reality. Here, also, comparing Herndon and Stutes is a study in polar opposites. Whereas Herndon is an extreme groundball pitcher (56.9%) with a lowish K-rate (6.03 K/9) and a lowish BB-rate (2.62 BB/9), Stutes is an extreme flyball pitcher (55%) with a high K-rate (8.62 K/9) and a high BB-rate (4.54 BB/9). Stutes's success is absolutely dependent on his ability to strike batters out, as more contact would mean more flyballs which would mean more home runs. Likewise, Herndon's success is dependent on his ability to keep the ball on the ground, as his low K-rate means hitters put the ball in play against him more often.
So what has been the difference between these two pitchers to this point? The answer -- and it may upset some fans to hear it -- is "luck". To this point, Stutes has benefitted from some good luck on balls in play. Even considering that an extreme flyball pitcher like Stutes with a solid 16.4 infield flyball percentage would naturally have a lower BABIP because BABIP on flyballs tends to be lower, his current .216 mark is simply not sustainable. Moreover, while the BABIP on flyballs is lower, flyballs also have a tendency to turn into extra base hits. Stutes can clearly be expected to regress, and his recent results indicate that that process is already underway.
Herndon, on the other hand, has had very bad luck on flyballs. This year, the league average HR/FB rate has been 7%. Herndon's has been an absurdly high 17.1%. Given that it is believed that pitchers generally are not able to control whether their flyballs leave or stay in the park, this number will almost certainly regress, and as it does, Herndon's ERA will also fall.
A quick look at each pitcher's DIPS would seem to confirm the assertion in the title of this post. Stutes's xFIP and SIERA are 4.38 and 3.71 respectively; Herndon's are 3.81 and 3.39. So not only has Herndon actually pitched better than Stutes, but he has done so by a considerable margin. Ranked by xFIP, Herndon has in fact been the third best reliever on the team among those with at least 10 innings pitched.
Herndon's terrible start to the 2011 season prompted many to declare him a waste of a roster space with little chance of developing into anything more than a back of the bullpen AAAA-type pitcher. Meanwhile, I urged perspective:
To sum up: People should not let their displeasure with Herndon's struggles in the earlygoing of 2011 cloud their interpretations of his past nor their hopes for his future. No one has ever argued that Herndon was a very good pitcher last year. What we have argued is that he demonstrated the potential to be a nice pitcher if certain parts of his game develop. It is not unreasonable to believe that these parts of his game could still develop. Even with his putrid start to 2011, this remains true.
Herndon was twice sent down this season--on May 4th and May 26th. Since his second recall on June 4th, he has been nothing short of excellent. In 18.2 innings, he has posted a 2.89 ERA in spite of a .357 BABIP. Perhaps most impressive, though, is the fact that he has indeed improved his K-rate significantly, with 18 strikeouts and just three walks in those 18.2 innings. For comparison's sake, over the same span, Stutes has posted a 3.96 ERA in 25 innings despite a .200 BABIP. He has struck out 23 and walked 13 over that stretch.
Mike Stutes's early success this season and Herndon's early failures essentially solidified their respective places in the minds of fans. But imagine for a moment if Herndon started the season with the run he has been on since his recall. Imagine if Stutes had started the season as a 4.00 ERA pitcher. How would things be different?
In any case, all of the data above suggests that now in just about any situation Charlie Manuel would feel comfortable using Mike Stutes, he should feel even more comfortable with using David Herndon.