Friday, May 16, 2008

The Truth About Boof

I was going to spend today's post writing about a costly lack of fundamentals that caused the Twins to lose three straight games against the Blue Jays this week, thus putting a disappointing cap on a homestand that started out so promisingly. But instead, there's another topic I'd like to delve into. And that is Boof Bonser.

After his latest poor outing on Wednesday night, fans are turning on Bonser in droves. For whatever reason, it seems like much of the fan base has always had it in for Boof, and his latest three-game slump has brought complaints to a fever pitch. The Twins generally have a fairly intelligent and patient group of followers, so I have to say I'm a little surprised by what I view as an extremely unfair fan response to Bonser's struggles. Not only would a demotion to the bullpen or minors for Bonser be reactionary and unwarranted, it would be downright stupid.

Bonser's last three starts have been ugly, there's no doubt about it. During that span, he has allowed 16 earned runs over 16 innings for a 9.00 ERA. Yet, it seems to me that the fans who are complaining loudly about Bonser's performance this year are either plagued by short-term memory or are actively choosing to ignore the good things he's done. Over his first six outings of the season, Bonser tossed five Quality Starts, though he gained only two wins thanks to some lousy run support. Bonser finished the month of April with an ERA under 4.

Even with his past three starts taken into account, Bonser's numbers for the season really aren't that bad when you take a deeper look. Yes, he is 2-5 with a 5.37 ERA, but his case illustrates a perfect example of why win/loss record and ERA are not the most telling measures of a pitcher's performance, in spite of the fact that they are the ones most often quoted in the media.

Let's compare the performances of Bonser and the team "ace" Livan Hernandez on the season. As I mentioned, Bonser has a 2-5 record and an ugly 5.37 ERA through nine starts, whereas Hernandez has surprised everyone by going 6-1 with a 3.90 ERA over the same number of starts. Looking at those numbers, one could easily conclude that Hernandez has been the better pitcher. But taking a look at some more intuitive statistics, we'll find that this isn't necessarily true:


Bonser

Hernandez

IP

52

57.2

K/BB

33/15

21/11

HR Allowed

5

9

Opp. OPS

700

820

FIP

3.92

4.21

xFIP

4.48

4.59


Bonser and Hernandez have both gotten roughly two strikeouts for each walk, but opposing hitters have slugged just .390 against Bonser, as opposed to .485 against Hernandez. This is a big part of the reason that fielding-independent statistics like FIP and xFIP indicate that the two pitchers have been a whole lot closer in performance than their win-loss record or ERA will tell us.

Now, to be fair, I'll note that Bonser is likely to start giving up more home runs, because his current 7.8 percent home run/fly ball rate is unsustainably low (Hernandez's is 13.1), but it's also worth noting that Bonser is currently only inducing ground balls at a 38.4 percent rate after posting percentages of 45 and 41.7 in his first two seasons, so we can expect him to cut down on the fly balls to some degree. Meanwhile, Hernandez's current 42.7 percent ground ball rate is likely to come down given that he hasn't posted a GB% over 40 since 2004. Moreover, I suspect that Bonser's K-rate will rise at least a bit, while Hernandez isn't real likely to start missing any more bats with his 85-mph "heat."

All of this is a very long-winded way of saying that Bonser has not pitched as poorly as his numbers indicate, and that there's actually a pretty good argument that he has pitched at least as well as Hernandez. Now, don't get me wrong, I'm not one of the people that swears by statistics like FIP and DIPS to the point where I blissfully ignore reality. Hernandez has allowed fewer runs and has helped the Twins win more games, and he deserves commendation for that. But there is plenty of reason to believe that the hefty Cuban is due for some decline while Bonser improves, so one month from now I think we could very easily be hearing the same cries of outrage directed at Hernandez. And I hope people will be counting their lucky stars that Bonser wasn't sent down to Rochester.

3 comments:

Judd said...

Nick- Good stats, bud. Interesting that much was made of Boof's stamina before he dropped the lbs., and now it seems as if that 1st inning is his white "whale."

Judd
C.P. Twins Blogger

Anonymous said...

Hernandez has allowed fewer runs and has helped the Twins win more games, and he deserves commendation for that.

The team has allowed fewer runs with Hernandez on the mound and the team has won more games with Hernandez on the mound, and the team deserves commendation for that. Pitching and run prevention are two different things.

As I've basically been saying all along, Boof is a mediocre pitcher who will eventually be labelled as an inconsistent pitcher, because that's what fans do to mediocre starting pitchers. See: Lohse, Kyle.

For whatever reason, everyone tries to find a story with Boof where there just isn't a story. We had the nonsense about Boof magically becoming a pumpkin in the sixth inning last year, all of the worries about his weight, and now the ridiculous call to essentially throw Boof out of the league. Through all of it, Boof has been a mediocre pitcher--essentially the mediocre pitcher that his minor league record suggested that he would be.

Anonymous said...

At what point do you send a pitcher to the pen and expect great results? One example would be J.C. Romero, we knew he got rocked after the 5th inning. But what of Boof? Could he be an effective middle reliever? He would not have to rely on as many pitches, and he still has good enough stuff to strike out a fair percentage.

That said you have to keep him in the rotation, for now. Boof consistently gets to the 7th, he is essentially what we hoped Livan WOULD be - an innings eater. We need that now with an overtaxed bullpen.