Zach Duke (AP)

Thoughts on Zach Duke

I've received a lot of questions lately about Pirates rookie lefty Zach Duke, who has been little short of brilliant since being promoted to the Majors in early July. He's 6-0, 1.87 in nine starts, with a 42/16 K/BB in 57.2 innings, allowing 54 hits and just two homers so far. Before his promotion, he was 12-3, 2.92 in 16 starts at Triple-A Indianapolis, with a 66/23 K/BB in 108 innings, 108 hits allowed, eight homers. As you can see, he's been even more effective in the Show than he was in the minors.

What does the future hold for this guy?

First, let's review where Duke stood at the beginning of 2005. Here is the comment I wrote about him for the 2005 Baseball Prospect Book.

"Zach Duke emerged as one of the best southpaw prospects in the game last summer, dominating competition at two levels. He did this without a blazing fastball. His best heater is 90 MPH, and he often works at 87-88. But he gets good movement on the pitch, and keeps it low in the strike zone. The contrast with his fine curveball makes the fastball look faster to the eye than the radar gun. His changeup isn't as refined, but should get better with more experience. His conmand is very good, and he changes speeds with the fastball and curve very effectively. My only concern here is his low strikeout rate in Double-A; his K/IP was weak at -12 percent. Sinkerball guys can get away with that sometimes. . .but not always, witness Sean Burnett. Duke is a fine prospect and deserves a Grade B+ based on his performance last year, but he's not a sure thing just yet."

Duke ranked 33rd on my list of Top 50 Pitching Prospects.

Reviewing my analysis of Duke, I think it was pretty solid even though he has exceeded my expectations so far. Interestingly, his K/IP ratio for Pittsburgh is 6.55 K/9IP, compared to 5.50 K/9IP this year at Indianapolis. His K/IP has actually been considerably better in the majors than it was in the minors. Can he keep that up?

As noted, he keeps the ball down very well and generates grounders, which helps him succeed despite the lack of big-time K-rates.

So, where does he go from here?

Beware small sample sizes!. Yes, Duke has had an impressive debut, but the league can and will adjust at some point. He's not the kind of pitcher who has a huge margin for error, and he'll need a good defense behind him to win consistently. If I had to guess, I'd say that Duke will be a league-average starter in 2006, with the chance to move beyond that into John Tudor/Jimmy Key Successful Finesse Lefty Land if he stays healthy. The Pirates are already talking about backing off his workload for September, which I think is a good idea.

I'm putting a poll about Duke in the comments thread.

UPDATE A reader notes in the comments that Duke is throwing harder this year than last year, bumping his fastball into the lower 90s more consistently.