Marshall's finishing position is clearly difficult to sustain. But what about his 2007 performance thus far? WHIFF gives Marshall and the Cubs some reasons to be optimistic.

(Original article on WHIFF Rate can be found here.)

Sean Marshall is currently 2-2 with a 2.05 ERA. He's thrown four quality starts in all four of his 2007 outings, has a WHIP of 1.04, and is striking out a batter per inning to boot. This is a far cry from his big league line in 2006, and, statistically speaking, it will be nearly impossible for him to sustain his ERA and BABIP (.257). But is Marshall, at the very least, "legit"?

Well, the reality is this: Marshall's success this season almost certainly coincides with a radical transformation in his pitching repertoire. Last season, Marshall relied on mixing his fastball and changeup, sometimes even officially pitching backwards by throwing more changes than fastballs in single starts. His changeup (82.8mph) lacked a great deal of velocity separation from his fastball (87.8mph). Marshall was essentially at the mercy of whether he could out-finesse hitters.

His approach is much different this year. While he still throws a bunch of elbows and kneecaps at the opposition, something that provides critical deception, he also attacks them, especially righties, with his fastball and a hard slider. In fact, his slider (a pitch that has morphed from a rarely-used and sometimes invisible cutter last year), has become Marshall's second pitch. And his changeup, at least in his last two starts, has been ditched almost completely (only 2 thrown).

But maybe the most important development has been the effectiveness of Marshall's curveball. While his fastball and slider are mostly pitched to contact (even though his fastball ranks high with a .182 WHIFF Rate, well above the .131 MLB average), his curveball has been an outstanding swing-and-miss pitch, producing a WHIFF Rate of .452, well into the upper tier of curveballs in baseball. Only A.J. Burnett (.535), Francisco Rodriguez (.494), Doug Slaten (.469), Justin Duchsherer (.463), and Brett Myers (.460) have better rates than Marshall (using 40 swings as a minimum).

While the sample size isn't ideal, it's substantial enough to conclude that Marshall is capable of achieving an above-average K-rate, and eat up enough innings to be a solid big league starter.

Sean Marshall - WHIFF Rate Breakdown

Fastball - .182 (MLB Avg .131)
Curve - .452 (MLB Avg .241)
Slider - .228 (MLB Avg ..273)
Change - .000 (MLB Avg .250)