How Long Will MLB's Perfect Pitchers Remain Perfect?

If you had tried to guess before the season which three pitchers would still have a perfect record come June 17, I highly doubt you would have guessed Max Scherzer, Clay Buchholz, and Patrick Corbin. I know I would have been far, far away from the truth.

OK, maybe Scherzer would have been easy to get; his 11.1 SO/9 did lead the majors last season, after all, and he does have the Tigers lineup behind him. But Buchholz had never had a strikeout rate above 17.0 percent or a WHIP below 1.2 over the past four seasons, while Corbin went just 6-8 in 22 games (17 starts) last season in his first career MLB action.

None of these guys are likely to be perfect at the end of the season; I'll be surprised if there are multiple perfect pitchers even come the All-Star Break. But it's worth looking at their numbers to see how they've gotten this far and what to expect from them the rest of the season.

Max Scherzer

The Great - I really can't say enough about Scherzer's strikeout rate. At 31.0 percent of opposing plate appearances, Scherzer's strikeout rate is the second-highest in the majors behind Yu Darvish among pitchers with at least 250 batters faced. And the craziest part is that it seems mostly sustainable - Scherzer has a career strikeout rate at 25.0 percent and was at an MLB-best 29.4 percent last season.

The Good - Strikeout pitchers are often all over the map with their control as well, but you can't say that about Max Scherzer this season. His 6.4 percent walk rate is the best mark of his career and is over a full percentage point down from his 7.6 percent mark last season. It's also just the 60^th most among 97 qualified MLB pitchers. Those walks are one piece to the majors-leading 0.875 WHIP puzzle.

The Bad Omen - The biggest piece to the puzzle, though, is his also majors leading 5.7 hits allowed per nine innings. Given Scherzer's past numbers, however, that low hit rate simply doesn't seem sustainable. His .244 batting average on balls in play (BABIP) allowed is miles below his .309 career average and .337 rate from just last year. Remember, all numbers regress towards the mean eventually.

When He Might Lose - The Orioles tonight represent a strong matchup against Scherzer, especially in terms of their above-average .302 BABIP going against Scherzer's career rate. However, as I discussed this morning, he still holds very high win odds. Scherzer's following projected start, against Boston and their MLB-leading .321 BABIP, represents an even greater challenge. Scherzer could fall soon.

Projected Rest of Season Stats

*Those 9 wins, by the way, are the highest projected total of any pitcher the remainder of the season. Those 128 strikeouts are second.

Clay Buchholz

The Great - Don't give up big hits, and your stats will respond. Buchholz's GB/FB ratio only sits at 0.94 this season, but even when he does let up fly balls, they're not doing any damage. 5.2 percent of opposing plate appearances have gone for extra-bases, the 10^th-lowest rate in the entire majors among qualified pitchers, and a third-lowest 0.6 percent of opposing plate appearances have gone for homeruns. That's a big reason his ERA remains a league-best 1.71 through two and a half months of the season.

The Good - Buchholz has always been solid limiting overall balls in play, and this season is no exception. Thanks to allowing only 20 percent of balls in play to be hit for line drives (actually the highest proportion of his career but still below the MLB average), Buchholz has allowed a .259 BABIP this season. That number seems sustainable as well; he was at .263 in 2010 and .265 in 2011. The resulting 6.1 hits per nine innings allowed, the sixth-lowest hit rate among qualified starters, isn't much of a surprise.

The Bad Omen - Jumpin' Johnny Pesky, where did those strikeouts come from? Buchholz has struck out 24.9 percent of opposing batters this season, leagues ahead of the four seasons prior when he never topped a 17 percent rate. That's what happens when you suddenly get batters looking - 52 percent of his K's have been backwards K's, the single-highest rate in the entire majors (his previous career high proportion was only 36 percent). Given regression to the mean, it should be expected that Buchholz will see his strikeout rate diminish, and his WHIP should go up in turn.

When He Might Lose - Clay Buchholz is cheating. Not in the traditional Roger Clemens sense, but in the "He may go on the DL and keep his perfect record because he's not pitching" sense. He was supposed to begin Boston's doubleheader against Tampa tomorrow, but he's already been scratched from that start. If Buchholz does go on the DL, there's no use in speculating when he'd return. He may just be the last man standing from attrition.

Projected Rest of Season Stats

Patrick Corbin

The Great - If you're going to have a 2.28 ERA, it starts with not letting guys on base in the first place. Patrick Corbin's 6.3 percent walk rate is actually higher than his 5.5 percent rate from last season, yet it's still a full percentage point better than league-average and in the top third of all qualified MLB starters. Corbin has been a master at getting ahead in the count this season; 70 percent of his first pitches are strikes, the third-highest ratio among qualified pitchers.

The Good - That 2.28 ERA is also easier to accomplish when you're barely allowing any roundtrippers. He may not hold Buchholz's insane homerun rate, but only allowing 1.2 percent of opposing plate appearances (and 3.2 percent of all fly balls) for homeruns isn't half bad itself. That places Corbin 10^th among qualified pitchers in homerun rate. I'm not sure how sustainable that is, though, considering his 3.1 percent rate last season with a slightly higher GB/FB ratio.

The Bad Omen - A .271 BABIP is good. Allowing 26 percent of balls in play to be line drives is not. A .271 BABIP and a 26 percent line drive rate mixed is unsustainable. But that's what we have in Patrick Corbin. The seams have slowly started to unravel; he's allowed six hits in each of his past four starts and a WHIP above 1.33 in three of those starts, yet he still hasn't lost. However, statistical analysis says that given a large enough sample size, the numbers will catch up with you eventually.

When He Might Lose - As you may remember from this morning, Corbin's got a halfway decent shot to go 10-0 tonight. The road ahead, though, is filled with more pitfalls than your Animal Crossing city. Next up on the docket is Atlanta, who holds an above-average OBP and slugging and whose one weakness isn't one of Corbin's strengths (strikeouts). Then comes Cincinnati, whose 24 percent team line drive rate is the second-highest in the majors. Then comes likely Colorado, whose 26 percent line drive rate is the highest. After tonight, it could get ugly.

Projected Rest of Season Stats