Is Edwin Jackson Clutch?

14 wins, a 4.42 ERA and 108 strikeouts. Not bad for a late-round flier, right?

Indeed, Edwin Jackson may have been the best fifth starter in baseball this year, and was a big reason why the Tampa Bay Rays won 97 games. However, much of Jackson’s success this year is unsustainable, and you should be very wary of him in 2009.

Let’s start simply: in 183 innings, Jackson posted a K/BB ratio of 108/77. If you’re going to strike out 5.3 batters per nine innings, you’d better do something else well – namely, you’d better limit your walks and/or get a lot of ground balls.

Unfortunately, Jackson doesn’t limit his walks, and doesn’t get a tremendous amount of grounders, either (he actually allowed slightly more fly balls than grounders this year). So what does he do well? Jackson was exceptional in “clutch” situations this year.

In fact, according to our handy “clutch” stat here at Fangraphs, Edwin Jackson was the third-most “clutch” pitcher in baseball. Of course, the better a pitcher is, the more likely is to be clutch – a good pitcher is more likely to retire a hitter in any situation than a bad pitcher.

Therefore, it’s of little surprise to see John Lackey, Cliff Lee, Tim Lincecum, and Jon Lester among the top 11 “clutchiest” pitchers in baseball this year. However, Edwin Jackson’s clutchiness is a big surprise: Jackson was far better in important situations than he was overall.

In fact, Jackson allowed an .830 OPS against him with no one on base, but a .752 OPS with runners on. With runners in scoring position and two outs, he allowed a .682 OPS. With men on first and second, opposing batters got a hit only five times in 40 at bats. They were 4-for-17 with runner at third, and hit only .262 with runners in scoring position, as opposed to .281 overall.

Perhaps it’s possible that Jackson simply focuses better in important situations, allowing him to pitch better with runners on base. I am skeptical of this proposition in general, but I allow that it’s possible. If this were the case, we’d expect Edwin to exhibit similar splits in 2007 (when, incidentally, his K/BB ratio was a very-similar 128/88).

In 2007, his OPS against with none on was .847; whereas his OPS with runners on was 821. However, with runners in scoring position, his OPS against was .857. Batters hit .305 with runners in scoring position, as compared to .299 overall.

In short, Edwin Jackson displayed no ability to pitch well in the clutch in 2007. And he showed very little, if any, actual improvement in his overall game from 2007 to 2008. Rather, his “improvement” is tied directly to his splits with runners on base, leading him to give up far fewer runs than he “should” have. Unless you think that this is actual improvement in his “clutch” pitching – which is extremely rare and not backed up by the numbers – look for Jackson’s ERA to rise, perhaps significantly, in 2009.