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Luck Independent Pitching Stats, Homer to Flyball Rates, JJ, and You

edit 1/1/07: [Aww fuck.

Turns out that the home run to fly ball numbers I used for this were wrong. My fault, too.

The points I make are still broadly true (Jennings' fly ball rate WAS up in 2006; Dan Wheeler DOES give up fly balls to left without giving up a great deal of homers), but the homer to flyball ratios are just wrong.

If just coming to my site, your time would probably be better spent reading something else.

I'd delete the whole thing and simply revisit the idea later, but that would look cowardly. Better to admit when I'm wrong in full view.]


A new article at The Hardball Times says Jason Jennings was the second-luckiest pitcher in baseball last year.

I gotta admit, that kind of hit me where I live, because, upper-threes ERA in '06 notwithstanding, before that, I had been kind of used to thinking of Jennings as possessed of ERA's which, well, weren't that good.  Like over 5.00 and stuff.

And then here comes this article about Luck Independent Pitching Stats saying 2006 was a mirage, saying Jason should have had an (earned and unearned) runs average of 5.23.  Given how much I already miss Willy T (and how much Shamus misses Jason Hirsh), it was the last thing I'd wanted to hear.

But after thinking about it some, after having looked at Jennings last week when I was reviewing all the BIPchart info, I think I've come to the conclusion that this article doesn't bother me that much after all.

Basically, the purported problem with Jenning's 2006 ERA is that he allowed about 9% of his outfield flies to leave the yard.    The author of the article, David Glassko, makes the contention that pitchers have very little control over that flyball-to-homer percentage, that all pitchers will tend toward the league average, which over the last four years was 15.7%.  The difference between the 9% Jennings allowed (17 homers) and the 15.7% they say he should have allowed (27 homers) is gonna be the primary ingredient in the difference between what we know his ERA was and what this LIPS system says his RA should have been.

But the thing is, I'm not necessairly inclined to believe the assumption.  When I was talking about Jennings last week, when I was looking at the BIPChart stuff, I'd noted that his flyball ratio was up 4-1/4% in 2006, and since most of that 4.25% jump was to center and right, I had kind of half-ass theorized that here was a pitcher who was allowing his park to work for him, and WOULD allow his park to work for him when he took up  residence upon the hill at Minute Maid.

I keep thinking of the few critics who disliked the Jennings trade from the Rockies' point of view.  "OK," they said.  "Let me get this straight.  You've finally found a pitcher who's figured it out, figured out how to pitch at Coors.  And now you wanna get rid of him, and start over?"

Key phrase here:  "figured it out."  Jennings' home run to flyball rate was 16 point something in 2003, went to 19-something in 2004, and has dropped since:  to a below league average 15-flat in 2005, and thence to the 9.7% that bothered Glassko so much in 2006.  Might it be possible that this is the edge of a learning curve?

Just maybe?

Turns out that the LIPS data overestimated--gave us predictions higher than actual--for each of Colorado's five starters in '06.  Maybe this is the humidor turning the balls soggy, as Jeff Cirillo had complained.  Or maybe Jennings wasn't the only one getting smart about how to pitch in Coors.

I'm not sure, but I AM having a little problem with this idea of "luck".  

My guess is simply that the stats people who drive the research still quite haven't got a handle on what it is that a pitcher might do to keep his fly balls in the field of play.  Maybe they should look at Dan Wheeler.   Wheeler was second worst on the team in allowing balls to left field in 2006, AND had the highest fly ball rate of all. Formula for disaster, no? Perhaps if you're Fernando Nieve, but Wheeler allowed all of five homers during his 71+ innings of work in 2006, good for an excellent 0.63 HR/9IP, and good for a very nice 10.4% homer/flyball rate.

Now I don't know the mechanism that Wheeler used, but I don't think that the 10.4% in 2006 (or the 10.1% in 2005, now that I mention it) meant that Wheeler was lucky.  I think it meant he was good; I think it meant that he knew what the hell he was doing.

And humidor or no humidor, I think that a 3.78 indicates that Jason Jennings was good, that Jason Jennings knew what HE was doing, and such will be my opinion until it is proved otherwise.