2006 in Review- Zach Duke

Now that 2006 is over, I'll be looking at one or two Pirates and their 2006 season each day. I'll look at what we expected, what we got, and what that might mean for the future. I may or may not assign a meaningless grade to their performance. Today: Zach Duke.

2005 key stats: 8-2, 1.81 ERA, 1.20 WHIP 58 K, 23 BB in 84 and 2/3 innings at Pittsburgh
2006 PECOTA: 10-10, 3.87, 1.31, 117 K, 53 BB in 176 innings
2006 key stats: 10-15, 4.47, 1.50, 117 K, 68 BB in 215 and 1/3 innings

So what happened here? First off, we can probably throw ERA out, it's a very misleading stat. Baseball Prospectus put Duke's peripheral ERA (a complex stat, but lets just say it's his ERA based on his ERA, hits/9 innings, BB/9, K/9, and HR/9 that have all been adjusted for park, league, etc. ) from his stint at Pittsburgh last year was 3.25, meaning he was lucky last year. Still, 3.25 is a good PERA (it works the same as ERA only its not as dependent on things a pitcher can't control), so what happened this year? Not as much as people think, for starters. Duke's ERA+ (ratio of the league's ERA to his ERA adjusted for ballpark) was 100 this year, meaning he was exactly average. His BABIP (batting average on balls put in play, thus everything except strike outs and home runs) was .310, which his considerably higher than the league average of .290. This either means that Duke was very unlucky this year (among qualified pitchers only Andy Pettite had a higher BABIP this year at .312) or the Pirates defense flat out stunk (it was probably some bad luck and lots of bad defense).

The encouraging part about Duke's season are his first and second half splits. Before the All-Star Break he clocked in at 5-8 with a 5.17 ERA. He was walking almost 3.4 batters per 9 innings and only striking out 5.25. His WHIP over the timespan was 1.59. I don't know what happened after the break, but Duke dropped his ERA to 3.65 for the rest of the season. His strikeouts didn't improve (4.47/9), but his walks dropped to 2.19/9 and his WHIP dropped to 1.40. From the start of September he was excellent, dropping the number of hits allowed along with the walks and looking a lot like he did last year.

So what's the verdict? Baseball, especially pitching, is a game of adjustments. No one had a book on Duke last year and given his very good stuff, he dominated the National League. Being pegged as the pre-season ace of the Pirates this year, everyone studied up on him. The hitters adjusted to him and started to hit the ball better. Being a young guy, Duke took a while to adjust to what the hitters were doing, but eventually he rounded into form. He's still young (this year was his 23 year old season), but the way he ended this year was promising. Jim Colborn worked with him early in the year on some mechanical changes and they seemed to be taking hold by the end of the season. People likened this to fixing something that wasn't broken, but I kind of feel like it might've been more like getting your car inspected, a precautionary measure to make sure something doesn't break down the road. If Duke can just control his walks next year, something I think he can do based on his second half this year, I think the strikeouts will come up (he had decent K stats in the minors for a finesse guy and strikeouts are often the last thing to come for pitchers when they get to the majors) and he'll be a much better pitcher next year.

Stats from the Baseball Musings Day by Day Database, Yahoo! Sports, ESPN.com (they're the only ones that list current BABIPs for free), Baseball Reference and my trusty copy of Baseball Prospectus 2006.