Breaking down Bonderman

A Tiger season wouldn’t be a Tiger season without doubt about Jeremy Bonderman. In 2003 when he struggled out of the gate, there was much speculation that he was brought to the majors to quickly (which he may have been). He then shutdown Oakland. In 2004 after a particularly rough spell, there was talk of demoting Bonderman from the rotation or even sending him to Toledo. He then went out and struckout 14 White Sox. In 2005 he faltered down the stretch, was hit by a line drive, and people wondered if he was injured…and he was.

So when Bonderman dropped his second and third games, and struggled in the first inning of his fourth, there was a right to be concerned that the previous year’s injury was still around. Or perhaps we think to highly of Jeremy and he’ll never be the stud we thought he could be. Or he was rushed and never had a chance to develop that third pitch.

Even after bouncing back against the Angels, Bonderman’s ERA stands at 5.04 which is worst among the Tiger starters. But with a closer look at the stats, one could argue that he has pitched the best, or at least question why he hasn’t had better results. For these stats, I went to the always valuable Hardball Times.

FIP	3.35	4.85
ERA+	94	100
DER	0.744	0.692
LD%	15.70%	19.00%
GB%	47.70%	43.00%
IF/F	18.20%	11.00%
K/G	8.5	6.1
BB/G	1.9	3.2
HR/G	0.94	1.2
HR/F	11.80%	13.00%

Bonderman has K and walk rates that are considerably better than league average, and the best among Tiger starters. He also has allowed fewer homers than league average. Those 3 components help to explain why his FIP (Fielding Independent ERA) is the best on the Tiger staff.

Frequently when FIP is significantly less than ERA, it is because the defense isn’t as proficient at getting outs. In Bonderman’s case, the defensive has been well above average with a DER (Defense Efficiency Ratio) of .744.

Contributing to that high DER are the types of balls in play that Bonderman is allowing. His infield fly rate is high and his line drive rate is low. Two components that make things easy on the defense in that pop-outs are easy to field and line drives are hard to field.

So Bonderman is doing all the defense independent stuff well, and he’s getting good support from his defense, and inducing many fieldable balls. So how can he be sporting an ERA over 5? There is one more stat that tells the story:

LOB%	52.20%	70.00%

Jeremy has done a very good job keeping runners off base. Where he’s failed is keeping those who do get on from scoring. Now I have no idea why this is happening. It may be bad luck in terms of all the hits being bunched together. It may be that Bonderman is having trouble pitching from the stretch due to lingering arm issues. It may be that he lacks the focus with runners on base, or he changes his approach. In any case he is allowing a 904 OPS when runners are on base (a 571 SLG) as opposed to a 505 OPS when the bases are empty.

In 2004 and 2005 Bonderman’s LOB % held constant at 69%, which is very near the league average. Whether or not stranding runners on base is a repeatable skill I’m not sure. He has a history of being pretty average at it, and given all his other statistical improvements this year, I have a hard time imagining that this number won’t be corrected.

I don’t think there is any reason to be concerned about Jeremy Bonderman – other than typical injury paranoia about potential star pitchers. He’s had one rough game, and he’s pitched remarkably well in his other games. While I don’t know that he will continue to pitch at a 3.35 FIP rate, I’m quite certain that he won’t pitch at a 5.04 ERA rate either.