RoS ZiPS Nails Zach Duke, Can You?

Tuesday night Zach Duke tied a major league record by allowing hits to eight consecutive batters to start the game. The Cubs scored seven runs in the inning en route to a 9-4 laugher. In his last three starts, Duke has allowed 20 runs (18 earned) and watched his ERA climb 64 points.

Prior to this season, Duke had produced a FIP lower than his ERA three straight years. The most common explanation given for this was that the Pirates had a lousy defense. Then this season, Duke got off to a hot start and the improved Pittsburgh defense received a lot of credit.

After his June 2nd start against the Mets, when Duke allowed just one run in seven innings, his record stood at 6-4 with a 2.62 ERA and his name was trotted out as a potential All-Star candidate for the Pirates. He did not make the team initially, but was later selected as a replacement for the injured Matt Cain.

But even back in early June, there were signs that Duke was pitching over his head. Rest of Season ZiPS forecasted him to post a 5-9 record with a 5.11 ERA on June 4th. While there are still three weeks to go in the year, Duke’s record since the win over the Mets is 4-10 with a 5.05 ERA.

The Pirates still have an above-average defense. UZR/150 places them eighth with a 4.3 team mark, one closer to fifth place than ninth. And Duke’s ERA (4.02) still is lower than his FIP (4.38).

Even after his last three brutal starts, Duke has a BABIP 23 points below his career average. His LOB% of 74.3 percent is his best in the majors since his 14-game debut in 2005.

Some will point to the loss of good defensive players like Jack Wilson and Nyjer Morgan contributing to Duke’s slide since early June. Others will note that Duke appeared to take a step forward prior to his last three starts.

Duke has been a better pitcher in 2009. His K/BB ratio of 2.12 is his best mark since 2005. His O-Swing% of 29.9 percent is the seventh-best mark in the majors and a career best. Pitch Type Values shows both his fastball and curve being improved pitches, with his hook going from neutral/below-average offering to a plus pitch.

And with all of that, Duke is still essentially the same pitcher that he was in 2008. A season ago, his FIP was 4.40 and now it is 4.38. His tRA is 5.04 today and was 5.22 last year.

Going forward, can Duke maintain the gains made with his curve? Can he continue his pinpoint control (career-best 2.03 BB/9)? Can he continue to be one of the best pitchers in the game in getting batters chase pitches out of the strike zone? On the flip side, will Duke be able to stem a four-year trend of an increased flyball rate?

Duke has been both fortunate (BABIP, LOB%) and the beneficiary of improved defense. No matter which one you think has played a bigger role, how confident are you that it will be the same in 2010 for him? Just some thoughts to ponder for those of you in deep keeper leagues as you prepare your team for next season.





8 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
Charlie Saponara
15 years ago

Great write-up. I liked Duke as a sleeper for some decent ERA/WHIP numbers going into the season and was able to snag him off waivers before opening day. Still, I don’t think there was a single outing I didn’t grit my teeth just a little because of the low K rate. Luckily I traded him for Juan Rivera and missed his last 3 outings.

The addition of a two-seamer is what I think really helped his O-Swing%. In my opinion Duke can do more of the same in 2010, which is post an ERA around 4.00, but I’d be hesitant to keep him around due to the fact that he relies so much on the result of balls in play and that he just doesn’t contribute enough in the WHIP and SO categories.

Divakar
15 years ago

Interesting thought about the 2-seamer. It’s clearly there in Pitch F/X: a new pitch he throws 10% of the time. But it isn’t a separate pitch in the pitch value data.

If he is better with the pitch, then why has he sucked so bad since the ASB? How can we quantify the value of the 2-seamer?

Charlie Saponara
15 years ago
Reply to  Divakar

A sort of non-stat explanation:

Duke used the pitch as a nice “complimentary” offering that may have kept hitters that much more off balance. Duke has been pitching a bit over his head all season anyway (using his low BABIP against as an indicator) and hitters may have simply made the adjustment. Or perhaps balls that were outs before are now falling in for hits.

A good comp would be Jarrod Washburn, who also added a two-seamer this season. The low BABIP didn’t last when he moved to DET.