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Don’t Blame Duke

Now a full fifty games under .500, the Pittsburgh Pirates hold, by far, the worst record in the majors. The Bucs have “earned” that sordid status, and then some. The club has been outscored by 287 runs this season, giving them a Pythagorean record of 42-104 instead of their actual 48-98 mark. There are signs of progress — Andrew McCutchen, Pedro Alvarez, Jose Tabata and Neil Walker form a quartet of talented position players, and the organization’s pitching depth has increased. But Jameson Taillon, Stetson Allie and Luis Heredia aren’t walking into the PNC Park clubhouse any time soon, and while prospects like Bryan Morris, Brad Lincoln, Rudy Owens and Jeff Locke offer promise, none are considered top-tier talents. There’s help on the way, but there are no guarantees. And James McDonald aside, the current rotation is getting trounced.

Zach Duke has become the poster boy for Pittsburgh’s pitching struggles. The lefty has been a fixture in the team’s rotation since 2005, but a disastrous stretch since the beginning of August (44.1 innings pitched, 38 runs allowed) had the Pirates considering banishing him from the starting five. In 141.2 IP this season, Duke has a 5.78 ERA. That’s the highest figure among starters who have tossed 140+ innings — most guys who get crushed like that get hooked off the stage. Some Pirates fans are ready to make Duke walk the plank, advocating that the team get rid of him instead of tendering him a contract for his last season of arbitration eligibility in 2011. But I’m left wondering, is he really pitching that much differently than in years past?

Duke has both struck out and walked more batters per nine frames in 2010, but we’re speaking in relative terms. Pittsburgh’s 20th-round selection in the ’01 draft has 5.65 K/9 (4.73 K/9 career) and 2.92 BB/9 (2.45 BB/9 career). His 47.8% ground ball rate is close to his career 48.9 GB%. Duke’s expected fielding independent ERA (xFIP), based on his K’s, walks and a normalized home run per fly ball rate, is 4.41. His career xFIP? 4.38.

Like his rotation mates, Duke is a pitcher who often puts the ball in play. Unfortunately, the guys behind him have done a terrible job of converting those balls put in play into outs. The Pirates’ lineup has transformed drastically over the course of the season, but on the whole, the team has been about 48 runs worse than average, according to Ultimate Zone Rating. Only the Indians have been more inept with the leather. Per Baseball Prospectus’ Defensive Efficiency rating, Pittsburgh has converted the lowest percentage of balls put in play into outs (67.5%) of any big league team. Duke has a whopping .351 BABIP, highest among all MLB starters. While his career BABIP is elevated (.325), in part due to other lumbering Pirates teams, he has especially been the victim of a combination of poor luck and lousy defense in 2010.

He’s also finding fly balls that died at the warning track in past seasons are reaching the cheap seats this year. Duke has surrendered 23 home runs, or 1.46 HR/9. His home run per fly ball rate has jumped to 14.6%, compared to the 10-11% MLB average and his career 10.1% career mark. According to Dan Turkenkopf of The Hardball Times, PNC Park decreased homers per fly ball hit by six percent over the 2006-2009 seasons. If Duke had coughed up a homer about 10.3 percent of the time a fly ball was hit at home (the average HR/FB rate, multiplied by .94) and 11 percent on the road, he would have given up 18 HR, or 1.14 HR/9.

Despite the macabre ERA, Zach Duke is basically the same starter he has always been –ZiPS projects that he’s a 4.37 FIP pitcher moving forward. Duke is making $4.3 million this season, and even with ugly surface stats, he would likely get a modest salary bump in arbitration. Pittsburgh could non-tender him and move on, or they could try to bring him back at a lower rate. I think that he’s worth bringing back and is a serviceable starter in a vacuum. But the Pirates haven’t done Duke, Paul Maholm and other low-K arms any favors by so often failing to get to those grounders and cover the gaps. Collectively, Pirates starters have a 4.78 xFIP. That’s bad, worst in the NL in fact. Even so, that looks sparkling next to the team’s actual 5.44 ERA.

The club has to hope that Alvarez, Walker, Tabata et al take to their positions well, because starters who don’t miss bats and fielders with limited range go together like oil and water.