What's Up With...? Chad Qualls

This is the first in a vaguely-regular series where we pick apart the numbers for one of the Diamondbacks - whether they're doing well or badly - in an effort to see if we can find any reason for their recent performance. We start with Arizona closer Chad Qualls,who has struggled through the first couple of weeks, saving only one game in his first three attempts, and posting an ERA of 8.44, to follow on from a disappointing spring. Barely ten games in, discussion had begun about replacing Qualls as closer, though the heir apparent, Juan Gutierrez, didn't seem like much of an improvement.

Then, in the middle game against the Cardinals, good Chad returned, mowing down St. Louis with a perfect inning, including two strikeouts. But it was a brief appearance, and the next night saw him get tagged with  three earned runs while retiring one batter. So, after the jump, we ask... What's up with Chad Qualls?

Chad's 2009 season came to an unfortunate end, as he dislocated his knee after the Astros' Jason Michaels hit a line drive to the mound during a game on August 30th at Chase Field. The ball deflected off Qualls' glove - though the out was obtained and the save records, as our closer spun awkwardly on the play, and crumpled to the ground with a dislocated knee-cap. "I remember twisting to get out of the way and then hearing what you hear when your back cracks - you know, that crunching noise? - and then I just felt an immense amount of pressure on my kneecap," said Qualls this spring.

He underwent surgery in September by Team surgeon Dr. Michael Lee, who went in to repair the damage to the tendons and muscles inside Qualls' knee - this was followed by another procedure on December 8th, to break up scar tissue and improve flexibility. Initially, spring training seemed to go well, with Qualls proclaiming, "I told them you don't need to hold me back or anything," and his first few appearances went well. However, the wheels completely fell off in the contest against the Royals: in a game filled with awful performances, Chad's was the worst. He allowed six earned runs while retiring one batter, and ended spring with a 7.45 ERA, allowing 12 hits in 9.2 innings.

The regular season started no better. Over his first six appearances, the only one in which he did not allow a hit was the final out in the blowout win over the Pirates. In those 5.1 innings, he has allowed 10 hits and an uncharacteristic three walks - in 2009, he allowed his third walk in his sixteenth inning of work. However, Tuesday night then saw the apparent resurrection of the old Qualls, retiring the Cardinals in order, without letting a ball out of the infield, to close out the victory over the Cardinals. What was the difference? In one word: location.

The charts below show, in the upper diagram, Qualls' pitches from the beginning of the season up until Tuesday, and then in the lower, his pitches against St. Louis that night. Think of the pics as a snapshot from the catcher's point of view, showing whether pitches were high, low, in or out. The color of the dots indicates the pitch-type - fastball, sinker, slider and change-up - and the square in the middle is an approximate strike-zone.

The difference should be immediately obvious. Qualls went back to working down towards the knees of hitters - not a single one of the thirteen pitches thrown against St. Louis was above the middle of the zone. The results? two swinging strikeouts and a groundball back to the mound. Contrast the amorphous blob of pitcher thrown before that appearance, including a disturbing number of fastballs that weren't even close to the plate.

On the broadcast, they were speculating that Qualls may pitch better on zero days' rest. The theory is that when he is fully rested, he overthrows his pitches; when he is slightly-fatigued, he takes a little off, and this makes the ball move more. It's difficult to find specific evidence from the pitch f/X data with regard to what happens to his pitches on zero days' rest, but it is worth noting that, in his career, Qualls had a 3.23 ERA over 128.1 innings when he worked the previous day. That's a little lower than his overall number (3.38), despite a BABIP 17 points above his career rate.

However, there are some worrying signs elsewhere in Qualls' numbers.

1. His velocity is clearly down. Qualls' fastball this year is averaging 91.7 mph, compared to his career average of 93.2. The same goes, but even more so, for his slider: it's 85.0 mph in 2010, down almost two miles per hour from his career number of 86.9 mph. His two-seamer? 92.3 -> 90.9 mph.
   
2. The vertical movement he is getting is also sharply diminished. Overall, his fastball has gone from moving 2.8 to 1.5, his slider from 2.5 to 1.2, and his two-seamer from 1.0 to -0.4. Given that's basically Qualls' entire armory - he doesn't have much of a change-up or curve - seeing it turn into what Mark Grace would call a "hovercraft" is worrying.
3. The first two factors may be why batters are making more contact. A lot more contact. When they swing, they hit the ball 94.0% of the time so far, well above both the 2010 average of 80.7% and Qualls' career number of 76.8%. In particular, when he gets batters to swing at pitches out of the zone, their chances of making contact has rocketed to 80%, from a career number of 45.6%

The figures from his successful outing on Tuesday showed approximately the same speed on his pitches, but a great deal more vertical movement. That is probably what resulted in the batter only being able to make contact on one of the four swings taken during the inning. But then, Wednesday night saw him back to hanging pitches which the Cardinals promptly clobbered. Qualls only managed to throw ten pitches, so the sample size is even smaller, but here's where those deliveries landed. If you have read this far, I doubt I have to say anything except "middle of the strikezone".

In an interview, Qualls said that he needs to get on top of the delivery in order for the ball to sink and be effective. When he isn't, getting around the ball, it flattens out and doesn't drop like it should. That clearly seems to be happening this season. Jack Magruder reported, "On Tuesday morning, Chad Qualls watched videotape with pitching coach Diamondbacks Mel Stottlemyre Jr. and noticed a small flaw in his delivery that was causing a problem with the plane of his breaking ball." Tuesday night: fine. Wednesday night: not so much.

Could it be an after-effect of his knee surgery, possibly throwing his mechanics off? Qualls denied this, saying after the latest implosion, “I feel great. My knee feels fine. It’s just the way baseball goes. You just have to keep grinding it out.” But it's definitely troubling, and I suspect that sooner rather than later, Qualls will need to be relegated to lower-leverage innings, at least until he has shown he can consistently deliver the ball in an effective manner. Because 13 hits in 6.2 frames of work simply isn't getting it done.