The Cubs won two in a row in Chavez Ravine, taking a series against the Dodgers before a flight home and a day off. The wins came on the back of some strong starting pitching (not to mention Carlos Pena finally going deep--two games in a row). Ryan Dempster and Carlos Zambrano both came through, with Demp's strong performance standing in contrast to the general ugliness of April.
Big Z was up-and-down in April. Dempster had some good runs, but was taken down by big innings in his first couple starts. Before the Dodger game, Dempster had lasted just a third of an inning in Arizona last time out.
His struggles are not easy to boil into a nutshell, or a simple and elegant mixed metaphor, but I get the feeling it's the sinker and it's not necessarily a big problem.
Dempster's pitching lines started out looking questionable and went downhill from there. IP and GSC (game score) are nearly sufficient, but details are provided for your enjoyment displeasure edification.
DATE IP GSC H ER K BB HBP HR Apr 1 6.2 41 6 6 4 7 0 2 Apr 6 7.0 45 10 4 6 0 0 0 Apr 11 6.1 51 6 4 9 3 0 2 Apr 17 5.0 35 7 5 4 2 0 1 Apr 23 5.2 23 9 7 3 3 0 3 Apr 28 0.1 11 4 7 0 4 1 1 May 3 7.0 64 6 1 5 2 0 0The first few games were a hem-and-haw of "maybe Quade left him in too long" or "really just one bad inning", but holy smokes he closed out April in a pile.
Gaining some perspective on the struggles require a frame of reference. In Dempster's case, it's his performance since his return to the rotation in 2008. Each pair of numbers will have 2008-2011 rolled-up (left pane) and each start in 2011 isolated (right pane). Click to enlarge.
First problem is kinda obvious, Demp's whiff rate has been off his standard. His standard is well above average and the drop is just to about average. Alarming just the same. There was no sign of hope evident in a recovery based on his strong performance in L.A., although he seems to have found the Dodgers willing swingers of the bat.
Fools, swings out of the zone (chase) or takes in it (watch), are based on the a strike zone defined by the "rule book", which is the plate plus a ball and, for the top and bottom, a combination of Gameday strike zones and the batter's actual height.
It appears Dempster had the Dodgers eager to swing to the point they were going out of the zone at a high rate. It wasn't pure aggression--they took some strikes.
As noted above, the Dodgers took strikes and chased balls out of the zone. That's reflected in the nice B:CS ratio Dempster got from the umpire. The "wide" zone is a full two feet across, but Dempster ain't throwing much in it. As with the low whiff rate in the "good start" on May 3, Dempster's ability to throw strikes was not up to his standard. Perhaps.
It was the opponent who balanced the results, by swinging at the wrong pitches. Maybe Dempster was exploiting this and exhibiting great control by staying out of the zone. In any case, I'm not to thrilled about the strike throwing and bat missing, despite the fine overall resul.
Batted balls tell a little bit more of the story.
Dempster's line drive rate has jumped, at the expense of his fly ball rate. When I see this, I wonder how much is simply "that ball was a hit, so it's a line drive" is polluting the data. But we do see a "recovery" in ground ball rates, which were sub-par during the most treacherous of Demp's April starts. Dempster's low pop-up rate is due in part to a move away from the four-seam fastball, far and away his most effective infield fly maker.
Dempster's sinker love was clear early on this season, and would be related to not just the lack of pop-ups, but fewer strikes, whiffs and even more line drives when the shoulda-been-a-grounder gets licked.
So while it may not be a big deal, if Dempster continues to struggle he should consider reviving the four-seam to keep the keel even.
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