30 Questions: White Sox

Can Jake Peavy still be a fantasy ace?

Jake Peavy's is a curious case, as this might be an entirely different question had he not made it back from a torn tendon in his ankle and won all three of his late-season starts for the Chicago White Sox.

Funny what a best-case scenario recovery can do for a pitcher, isn't it?

When the White Sox traded for him July 31 -- the second time they had attempted a deal for him last season -- Peavy appeared to be no guarantee to throw another major league pitch in 2009. He had already spent seven-plus weeks on the disabled list and had yet to begin a rehabilitation assignment with only five-plus weeks to go in the minor league season, meaning his margin for error, specifically health setbacks, was precariously thin.

Remarkably, Peavy charged through his throwing sessions -- four rehab starts for Triple-A Charlotte, during which he had a 2.93 ERA, 1.17 WHIP and 9.98 strikeouts-per-nine ratio -- and then made his White Sox debut Sept. 15, going 3-0 with a 1.35 ERA, 0.85 WHIP and 8.10 K/9 ratio. And he did it all despite suffering a temporary setback when he was struck in the elbow by a batted ball in his Aug. 24 rehab start -- one that ended up not costing him any time at all.

Now, take that entire late-season success story and toss it out the window.

There are two reasons to do this: One, obviously, is the small sample size. Three starts are hardly enough by which to judge a pitcher, especially one in new surroundings fresh off a long-term injury. The other, and perhaps more important, reason is that Peavy's three starts came under favorable circumstances.

One of those three starts came versus the Kansas City Royals, who ranked 23rd in the majors in runs per game (4.23). The other two came versus the Detroit Tigers, who -- in addition to ranking only 15th in runs per game (4.56) for the season -- were mired in a bit of a funk at the time, averaging only 4.00 runs (80 total) in their final 20 games of the year, in eight of those games being held to two runs or fewer. If Peavy had to pick a time to face the Tigers, September was a good time to pick.

If you're going to evaluate Peavy's prospects for 2010, it would be smarter to take the 212 career starts he made for the San Diego Padres, adjust for the league and ballpark switch, and prepare accordingly based upon those numbers.

The ballpark switch is most troubling, at least if you account for Peavy's home/road splits since the Padres moved to Petco Park in 2004:

Petco starts (90): 2.74 ERA, 1.08 WHIP
Road starts (73): 3.40 ERA, 1.22 WHIP

Of course, a positive home/road split for any pitcher should be expected, considering that major league pitchers as a whole had an ERA 0.48 better and WHIP 0.08 lower in home games than on the road in 2009. However, Peavy's splits in those categories represent 0.66 and 0.14 differences, which is more than for your typical pitcher. Clearly, he gained a noticeable advantage from his home ballpark, which isn't surprising.

Take a look at these rankings of Peavy's two 2009 home ballparks, working backward in two key offensive categories the past five seasons:

Petco Park, runs: 30th (2009), 30th, 30th, 29th and 30th (2005).
Petco Park, home runs: 29th, 30th, 29th, 15th and 30th.

U.S. Cellular Field, runs: 9th (2009), 4th, 9th, 9th and 9th (2005).
U.S. Cellular Field, home runs: 4th, 2nd, 4th, 2nd and 2nd.

There's little doubt, examining those numbers, that the ballpark switch should have a noticeable effect on Peavy's ratios. For one thing, his days of a home run/fly ball ratio less than 10 percent might be gone. He is at 9.6 percent for his career and hasn't registered a double-digit number in the category since 2003. Don't expect that number to continue in Chicago. Tack on a couple more homers in his new home and he'll be no ERA title contender.

The switch in leagues, too, might have an adverse effect on Peavy's numbers. Last season alone, American League teams averaged 4.75 runs per game to the National League's 4.49, and that 0.26-run split also reflects the ERA differential between the two leagues (in other words, there wasn't really any imbalance in unearned runs between the two leagues). In the past five seasons, AL teams have averaged 0.11 runs more per game than NL squads (4.76-4.65).

Migrating to the AL Central should ease Peavy's transition somewhat, however. Considering that the Minnesota Twins (5.01) were the only members of the AL Central to rank higher than 10th in the majors in runs per game in 2009, it seems Peavy at least is in the right division for an NL pitcher making the move to the AL. He'll fatten up on more Royals matchups, while the only NL West team to rank among the game's bottom 10 in the category last season was Peavy's own Padres -- a team he obviously never got to face.

It's not unreasonable to think Peavy's ERA might rise a quarter-run simply from the ballpark factor, and another quarter-run from the league switch, resulting in a number closer to the low threes than the mid-to-high twos. Baseball-Reference.com offers what they call "Neutralized Pitching" statistics, converting a pitcher's numbers to a 162-game season for an average team in a neutral ballpark, and Peavy's "neutralized" ERA and WHIP in the past six years -- his best six to date -- were 3.33 and 1.23. It's fair to say fantasy owners should plan on his numbers falling within those ranges, not near his Cy Young stats, and remember that those numbers assume a neutral park -- which U.S. Cellular is not.

And statistics alone don't wrap up the Peavy package. Health is a significant question mark, considering that he has now made trips to the DL in each of the past two seasons, including once for an elbow injury in 2008, the very injury scouts have long cited as a concern, accounting for the torque his delivery puts on his arm.

Perhaps Peavy's missed time in 2009 might have eased some of the strain on his right arm caused by the 802 1/3 innings he threw the previous four seasons, but can anyone safely say he's a lock to make it through 2010 unscathed? After all, he did average 105.5 pitches per start from 2005-08, on 50 occasions threw 110-plus pitches and four times threw 120-plus. That's not necessarily abuse, but if Peavy's deliveries are more taxing than your typical pitcher's, they might be a bit much, meaning that a safe 30-plus-start campaign can't be considered a guarantee. Besides, he has only reached that plateau in four of the past seven seasons, meaning that the mid-to-high 20s, with a brief stint on the DL, seems an appropriate expectation.

Sum up the risks and, while Peavy does warrant fantasy attention, it's foolish to affix the "ace" label to him. Even 28 starts of a 3.20 ERA, which probably represents his statistical ceiling, isn't quite top-10 fantasy status, especially not for a team that ranked 19th in runs per game (4.47) last season and scarcely improved its offense during the offseason. A 20-win season is a long shot, an ERA title might be even less likely, and with each missed start Peavy's chances at a return to the 200-strikeout plateau get slimmer. Those are a lot of "ifs."

Peavy is being selected 22nd among starting pitchers in ESPN live drafts thus far, which might actually be a few spots too high. Here's a thought: What makes him any more likely to bounce back in 2010 than Roy Oswalt, who is being selected 11 spots later than him among starting pitchers?

The answer might be as simple as this: It's the three September starts, an advantage Oswalt clearly did not have.

Tristan H. Cockcroft is a fantasy baseball analyst for ESPN.com and a two-time champion of the League of Alternative Baseball Reality (LABR) experts league. You can e-mail him here, or follow him on Twitter @SultanofStat.