In case you don't read the Wall Street Journal regularly, you can check out Harry's article online here, no registration required.  In it, his research shows that the fives pitches that have induced the most whiffs per swing in 2009 (minimum 150 swings) are Michael Wuertz's slider, Zach Greinke's slider, Rich Harden's changeup, A.J. Burnett's curveball, Jorge de la Rosa's slider.  Since Harry's busy finishing off his presentation for the Pitch f/x Summit this weekend, I'm going to present some more interesting data from his whiff rate study, which he was kind enought to share with me.  Try this table, and there are threee more after the jump:

Highest Whiff Rates By Pitch Type, Min 150 Swings

I'm a bit surprised Johan Santan's changeup doesn't make the top five list -- he's down at 33.8%, sandwiched between Kyle Davies and Kyle Lohse.  Three other lefties are on the changeups list, which makes sense considering offspeed pitches are a great pitch choice against opposite handed hitters and the league has more right-handed batters.  The top five list that appeared in the WSJ contained three of the sliders above, although De La Rosa is the only lefty.  I'm impressed he's able to get so many whiffs with his slider as a starter who doesn't face a significant percentage of lefties.  No shockers in the curve ball column.

Highest Whiff Rates By Pitch Type, 75 to 149 Swings

Lowering the number of swings required to qualify brings a lot more relievers into the fold.  Javier Vazquez lands in both the changeups and curve balls columns.  He's been so good that you could argue he should throw either pitch more often, but then he's probably have to throw less of the other one.  What a great problem to have, Mr. All-Star Snub.  Joel Hanrahan is second only to Michael Wuertz in the slider category overall, and that near-50% whiff rate is a great sign for the Pirates, who just acquired Hanrahan.

Worst Whiff Rates By Pitch Type, Min 75 Swings

Ok, here we go, time to have pitty on some pitchers.  A 14% whiff rate on his changeup and 15% whiff rate on his curveball are certainly two reasons Bronson Arroyo has struggled this year.  Have the pitches been especially poor or has his inability to command his fastball made them less effective?  Given the success of many other pitchers with sliders as their out pitch, these guys in the middle column are a bit disappointing.  Is there anything different about the way they throw the pitch that makes it more of a contact pitch?  And with the curve balls, Barry Zito?  Really?  Now, I'm sure the frequency with which he throws it doesn't help, but is it time we change our impressions of Zito's strengths a pitcher?

Best & Worst Fastball Whiff Rates, Min 150 Swings

I've lumped all the fastballs together, for better or worse.  Four-seamers are F4, two-seamers and sinkers are F2, cutters are FC, and FA denotes a generic fastball (Harry was using a combination of Gameday classifications and his own home-brewed classifications.)  In general, it seems four-seemers are the best whiff-pitch, while two-seamers are better for inducing ground balls.  Cutters are more effective against opposite-handed hitters.

Among the impressive fastballs in the left-hand column, there are a couple surprising names, at least to me: Brian Tallet (that explains his breakout year), James Parr (who?) and Robinson Tejeda.  A lot of the other names are known for being fastball machines.  And up, that's Javier Vazquez showing up near the top of the whiffs leader board for a third pitch.

On the other side of things, Bronson Arroyo makes another appearance (what is going on?)  Two Mariners are on the list, holdovers from the previous regime.

What else did you notice while looking through the leader boards?  Certainly some intriguing information there.