Brandon Webb has, for all intents and purposes, been out of baseball for two years. The right-hander threw just four innings in 2009 and didn't appear at any level in 2010 thanks to bursitis in his right shoulder that required surgery. He was paid for his rehab though, with the Diamondbacks picking up his $8.5 million option for the 2010 campaign, so it's not like he went hungry by missing time.
Webb averaged 227 innings pitched a year from 2004 through 2008, along with 178 strikeouts and groundball to flyball ratios of 3.1 to 4.1. He struck out hitters at an average rate, but has never induced fewer than 62 percent of balls in play as grounders, more than making up for that. Asking him to step back in and dominate is a bit much given the time away as well as questions about how well his shoulder and stuff will hold up, but let's figure out what Webb might be now that he has signed a deal with the Texas Rangers for the 2011 season.
Webb's 2009 PECOTA forecast had him down for a 3.29 ERA, 212 innings pitched, a K/9 of 7.1, and a K/BB of 2.8 along with his usual anti-homer tendencies. That could have happened had his shoulder remained healthy, but since it did not, we'll never know for sure. His 2010 projection, while not aware of the nature of his injury (a little problem that Colin Wyers is working on for 2011) cut into his innings expectations, with 101 frames, but similar production (7.3 K/9, 3.75 ERA, another groundball rate above 60 percent).
His sinker was an "iconic" pitch, as described by Baseball Prospectus 2009, along the lines of "Nolan Ryan's fastball and Mariano Rivera's cutter". That was pre-injury, though. Velocity was never Webb's forte, but the movement on his sinker was phenomenal, which is how 30 percent of batters who faced him grounded out in 2008. Webb did all that with a nondescript defensive unit behind him as well; the Diamondbacks finished #21 in the majors in Defensive Efficiency in 2008 with 68.6 percent of balls in play converted into outs. That was their second-highest DER during Webb's peak years as their ace, so even if he's not 100 percent The Old Brandon Webb, the Rangers' defense should be able to pick him up more than the Snakes ever did, and might even make his WHIP more palatable for fantasy purposes.
With the switch to the tougher American League and things a little up in the air in terms of what his repertoire will look like when he finally does return to the mound, let's use Webb's 30th percentile forecast from 2010 as a guideline for what is to be expected of him (at least until the shiny new PECOTA forecasts are available). Webb's 30th percentile had a 4.19 ERA, 6.8 K/9, a 2.1 K/BB, and, unsurprisingly, a lifetime supply of groundballs.
For a safe estimate, that looks like a pretty solid pitcher for fantasy purposes, especially on a buy-low policy on a potential playoff team, and also when you consider extreme groundball pitchers may be better than we think. If he is healthy—an if of significant size given he hasn't touched a mound in a game since April of 2009—then there is no reason to think Webb will be anything over than what he has always been. That is worth the gamble in your drafts, and if your league mates agree, he may also be worth a few bucks more than a late-round, buy-low option normally would be. It's a shame your auction price can't include incentives like the Rangers' contract does, but if healthy he will be more worth than whatever you paid for him.