Can we call it a comeback?

It's hard to fathom that Carlos Silva has been a productive member of the Cubs' pitching staff through the first quarter of the season. When the Cubs acquired him in December in exchange for Milton Bradley, he had two positives going for him: he was a warm body, and the move saved the Cubs about $6 million.

Jeff Baker at the Seattle Times opined:

This is a huge deal for the Mariners. It's a no-brainer.

From Larry Stone at the same paper:

I understand why the Mariners are making this move -- Silva has absolutely no role on the team any more after two disastrous seasons and little hope for a turnaround. He went 4-15, 6.46 in 2008, and was 1-3, 8.60 in eight games in '09, spending most of the year on the disabled list. Bradley, at least, is healthy and can be very productive when he's focused and happy.

The blog Jorge Says No! added:

It has come to this. The Cubs were forced to take on one of the worst contracts in baseball just to get Milton Bradley off their hands. On one hand they should be celebrating that Milton is gone and they got some savings in return, but Carlos Silva has been one of the worst pitchers in baseball over the past two years.

I'm not trying to hammer these writers. Rather, their thoughts are representative of what pretty much every baseball fan thought about the trade. The Cubs had an albatross on their hands, were admittedly desperate, and agreed to take on a different albatross in exchange for their own. As Stone said, the man had an ERA over six the last two years--how else were we supposed to view the trade?

Brian Brennan, always looking for a way to snag an extra six-pack, tried to take advantage of Trevor Sierra's eternal optimism by betting him that Silva wouldn't even make the Cubs' Opening Day roster. Who could blame him? Silva was basically throwing batting practice the last two seasons--there's no spot on the 25-man roster for the batting practice guy.

But of course he did make the team, and now he's 5-0 with a 3.35 ERA. The Cubs are 7-1 in his starts. What in the world is going on here? Should we feel confident that he's back to his old form, or is this just a mirage, much like the thousands of people Milton Bradley sees yelling at him when he goes to bed at night? Let's take a quick look at his history.

While Silva was just plain awful with Seattle, he was offered a four-year, $48 million contract for a reason. From 2004 through 2007 with the Twins, he won at least nine games each year, had three seasons in which his ERA was 4.21 or lower, and amassed at least 180 innings all four years. (Not exactly a reason to dole out nearly $50 mil, but solid nonetheless.)

But even when he had success in Minnesota, lefties did significantly more damage against him than righties. In all four seasons, his WHIP and HR/9 were much higher against lefties. But when he went to Seattle, lefties really banged him around:

2008 vs LH: .348/.381/.555, 2.19 BB/9, 4.37 K/9, 44.5% GB%, 14.6% HR/FB%, .355 BABIP
2009 vs LH: .380/.436/.718, 3.94 BB/9, 2.25 K/9, 48.5% GB%, 21.1% HR/FB%, .359 BABIP

(hat tip: Dave Cameron, FanGraphs)

But so far this year, it's been a much different story:

2010 vs LH: .212/.264/.273, 2.45 BB/9, 5.89 K/9, 43.4% GB%, 4.5 HR/FB%, .247 BABIP

His WHIP against lefties is significantly lower than that against righties, and five of the six home runs he's allowed this season were to right-handed hitters. That FanGraphs article points out that Silva has altered his pitch selection to southpaws: he's using his changeup 40 percent of the time against lefties and 29 percent of the time overall, compared to 15 percent last year. Going away from his sinker has increased his fly ball rate, but to this point it hasn't hurt him. When the weather turns warm and the wind starts blowing out, this strategy could backfire.

Perhaps Silva is more comfortable throwing his changeup because he changed his position on the rubber prior to the season. From an emotional standpoint, it also seems entirely possible that he's been positively affected by his mother's presence here in the U.S. (see?)

Now, if Silva was going to have a misleadingly strong month, it would be April. He's 17-7 in that month in his career, easily the best record of any month. He also hasn't pitched in the NL since 2003, which means hitters don't have a good scouting report on him yet. There's also no question that his performance has regressed here in May. Probably the worst comparison to be found (in terms of being optimistic about his future performance) is the one originally posted at goatriders.org and then by Brian in the comments section of this blog:

Carlos Silva in first 6 starts of 2010:
3-0, 6 GS, 36 IP, 3.50 ERA, 1.167 WHIP, 7 BB, 24 K

Carlos Silva first 6 starts of 2008:
3-0, 6 GS, 42 IP, 2.79 ERA, 1.167 WHIP, 9 BB, 18 K

Carlos Silva in 2008 after those 6 starts:
1-15, 22 GS, 111 IP, 7.84 ERA, 1.760 WHIP, 23 BB, 51 K

All in all, it seems likely that Silva will continue to regress at least a little: he's never finished a season as a starter with an ERA as low as 3.35; his K/9 is the highest he's ever had; and his BAbip (average on balls in play) is also the lowest he's ever had (.283), though it's not so low as to be impossible for him to maintain.

On the other hand, he seems to have made some key adjustments that could enable him to perform much closer to the levels he was accustomed to in Minnesota as opposed to the struggles he encountered in Seattle. Few if any thought he'd be in the Cubs' rotation in mid-May, but perhaps the Cubs have found a fifth starter for the next two years.