Chad Qualls, Kevin Millwood, and Sample Size
The San Diego Padres have reportedly signed Chad Qualls to a one-year contract for about two million dollars in an effort to restore some of the bullpen depth they’ve traded away this winter. In signing Qualls, they are making a pretty big bet against the predictive power of ERA, considering he posted an atrocious 7.32 mark last year.
However, the Padres understand how to build a bullpen on the cheap, and they also realize that ERA is a pretty lousy way to evaluate relief pitchers. To illustrate the point, let’s compare Qualls’ season to that of another free agent, Kevin Millwood.
Qualls had the following miserable line last year: 59 innings, 85 hits, 56 runs, seven home runs, 21 walks, 49 strikeouts. That’s just not good, no matter how you slice it.
Millwood had the following miserable line last year: 51 innings, 86 hits, 54 runs, 11 home runs, 25 walks, 36 strikeouts. That’s even worse than Qualls’ performance.
The difference? That awful stretch of pitching represents just a portion of Millwood’s 2010 season – June 3rd to August 1st, specifically. For two months, he was every bit as bad as Qualls, but because he’s a starting pitcher, those 51 innings didn’t represent his entire season’s body of work. While he was brutal for that stretch, he got a chance at redemption through a larger sample size, and he took advantage of it.
Here’s Millwood’s line from immediately after August 2nd through the end of the season: 66 innings, 60 hits, 25 runs, 7 home runs, 23 walks, 38 strikeouts. After posting a 9.18 ERA in the middle two months of the season, he finished the final two months with a 3.26 ERA, despite not improving his peripherals much at all. The only real difference? His BABIP during the first stretch was .410, and his BABIP in the second stretch was .262.
I know its tempting to look at Qualls’ 2010 line and think that there’s no way he just experienced lousy defense and bad luck all year. A .399 BABIP is really terrible, after all. However, we have to keep in mind that it was just 60 innings, and starting pitchers have lousy strethces for 60 innings at a time too. However, because that only represents 30 percent of their season, we don’t notice these awful stretches as much, and when regression to the mean inevitably kicks in, it gets washed away entirely.
Since relief pitchers throw just a fraction of the innings that starting pitchers accumulate, they are subject to much larger seasonal variations. They don’t have time to regress to the mean in-season, and as such, you’ll see things like a pretty solid reliever in Qualls posting an ERA over 7.00. The Padres are willing to be that one 60-inning stretch doesn’t mean that Qualls is finished as an effective major leaguer, and given how Millwood finished the year for the Orioles, they have some pretty recent evidence to support the theory.
Dave is the Managing Editor of FanGraphs.
Spot on except for the very last sentence. Very well done.
I’m also willing to bet that Balsley will instruct Qualls to bring back a third pitch. Looking historically at pitch percentages, it’ll likely be the cutter — got Mike Adams to add a cutter and got Kevin Correia & Clayton Richard to use it considerably more often.
The BB rate last season is a little worrisome, but that could be within the error +/- once you consider that the per-nine numbers don’t consider the fact that the number of hitters you face per nine increases with BABIP.
The problem here is that those 60 innings still represent the entire season for Qualls.
What I’m saying is he would have had just as much time off the field as Millwood to correct any problems he may have had in his delivery. And either he didn’t, or he did and there are variations within his season too, meaning that the year he put up was his mean. Does that mean I’m saying he’ll have an equally horrible 2011? No. I agree that it’s very possible he bounces back, but it won’t be because he’s owed some statistical karma.
I just don’t think you can compare starter innings and relief innings the way you do here because they don’t exist over the same time frame in reality and you don’t only work on your effectiveness while pitching in the game.
(Also, right before the final two months, Millwood was on the DL and it is likely that during his span of ineffectiveness, he was actually injured.)
To assume that his BABiP will remain at .399 when for his career (including last year) it’s only .309 (over 470 IP) is to ignore a fair bit of relevant information. Also of note, and likely connected, is the fact his strand rate was only 53%, well below his career rate.
It’s precisely because of the fluctuations that can occur over the small number of innings pitched by relievers each year due to small sample sizes that a good reliever one year can be horrible the next, and vice versa, and why giving them multiyear contracts based on one or two good seasons is a horrible idea.
Okay, but I never assumed that. Why are you assuming I assumed that?
Sorry if I misinterpreted; this was based off of your assessment that he won’t improve simply based on statistical karma, and your assertion that reliever and starter innings are different. I likely didn’t word this quite as well as I should’ve, but what I was getting at was that he was subject over those same 60 innings to the same fickle fortune as Millwood was; even though he had time to figure out what was “going wrong”, what was going wrong was, simply, bad luck.
One should expect him to regress to the mean much the same as Millwood did.
With the “statistical karma” thing, I was implying that if he improves, it will possibly have more to do with him than it will merely him having better luck. The problem with projecting he will have better luck is that it projects several other things:
1) That there are gods of baseball who control what happens in a game and that they really hated Chad Qualls last year.
2) That the pitcher will be throwing exactly the same next year as he was the year before. To say it is merely chance ignores (and I realize this is somewhat blasphemous on a site like this) the human element of the game.
I guess what it all comes down to is I’m just more inclined to say, “Chad Qualls pitched like crap last year,” as opposed to, “Chad Qualls was incredibly unlucky last year.”
Only his pitching coach really knows…
Well, him and anyone who watched every inning he threw last year…
Or anyone willing to do a pitch by pitch analysis of his season…
And probably his wife and/or girlfriend.
It is somewhat unfair to state that he pitched like crap when his FIP was 4.13 and his xFIP was 3.98. Those are quite respectable peripherals (though high, for him, especially since his BB/9 increased a fair bit). The fact that his FIP is some three runs below his ERA indicate that while he pitched effectively, the results were poor (much poorer than could be predicted).
Assuming he maintains those peripherals next year (so yes, we assume he pitches effectively the same way, but he’s had a long enough career of doing this for it to make sense to do so), one should expect his ERA to drop from ridiculous (7.32) to the effective (3.84 BJ projection).
I’m afraid we disagree on the main matter at hand, in that I do assume that he was very unlucky last year (his BABiP was at an all time high, and yet he put up a career low LD%), and I think that, even if he doesn’t improve as a pitcher, his results will.
The BB/9 is a big thing to me. Seeing as how his rate was half a walk worse from his absolute worst year previous to this, it would seem that he lost some control. That’s not something that always comes back automatically. Some guys just lose the feel for it. And then that’s it. They’re done.
I seem to remember watching a Hot Stove look in last year where Qualls came into a game and he was kind of all over the place. Sure enough he ended up putting one right over the plate (like you tend to when you’re losing it) and that was it. He gave up the run. Game over. You put it right over the middle of the plate nice and easy and hitters are gonna make you pay for it.
Like I said, it’s not like I think he’s done. He has a really good chance of bouncing back if he can get the feel for the strike zone again. But if not…
I’m with Theo on this (ie. believe that pitchers, for the most part, have BABIPs which “regress to the mean”) … but this BP guy sounds like he’s more in Chris’ camp …
http://www.baseballprospectus.com/article.php?articleid=12779
Didn’t Qualls have some arm injury problems over the last couple of years? I would feel more confident that Qualls’ performance will regress to the mean if his arm is totally healthy.
Millwood could bounce back, but he was out of his element in Baltimore. The intangible was his slot in the rotation. I don’t think I remember anyone bringing up him being injured or complaining of arm soreness. He was asked to lead a young group of guys in a place he clearly didn’t want to be. I would put a lot of money on him bouncing back to more respectable numbers as a bottom of the rotation guy on a team in a warmer weather climate (AZ, SD, HOU?)
http://articles.baltimoresun.com/2010-07-07/sports/bs-sp-orioles-notebook-0707-20100706_1_disabled-list-strain-rick-kranitz
Excellent post. What do you think about the Mariners taking a chance on Millwood if the salary is right? I go back and forth on this one.
How the hell did you find these two comparables?
Do you have some type of searchable program or something?
I’m not even sure I remember what they article was about since I couldn’t get past “What made Dave think of Kevin Millwood’s horrible month? And how it compares to Qualls’ awful season?”
I’m impressed.
He’s a nerd with no life outside of baseball stats. No offense Dave. And really appreciate it. Hope you never get a hobby.
“How the hell did you find these two comparables?”
Go to Baseball Reference, Kevin Millwood or Chad Qualls, Gamelogs and use the aggregate function (for Millwood, click on his June 3 line then on his August 1 line)
With any luck, the Padres’ front office likes the comp so much they decide to bring Millwood in to lengthen their rotation. If they can sell him on a one-year make-good deal, playing in front of a damn good defense in the pitcher-friendly California NL parks, I think Jed can call it an offseason.
Backup catcher though, reportedly, they’re after Gregg Zaun.