It was improbable, all but inconceivable, really. Who, other than a certain group of blue-pinstriped men or a supernaturally prescient being, would say otherwise? But, incomprehensibly, Ryan Dempster has proved me very, very wrong: He has been a very good starting pitcher.

It was just a clever ploy masterminded by Jim Hendry, I told myself. Hendry would hope and pray that Dempster the starting pitcher would mow down the lackluster spring competition, and then leverage those mostly meaningless stats into a pre-season deal. Surely Hendry had no intention of letting Lou Piniella actually send Dempster to the mound every five days to start a game -- every five days out of the bullpen would have seemed more fitting. This, after all, was a pitcher whose career ERA as a starter bordered on five, who had not started a significant number of games in more than four years, and who is now on the wrong side of 30.

But there was no trade, no return to the bullpen, no spring training meltdown. And fantasy baseball owners snapped up Sean Marshall and Jon Lieber, just waiting for Dempster's inevitable failure and the subsequent hot-swapping. Perhaps they wait still; I hate to dampen this wondrous April, but regression to the mean is an inescapable foe. But fear not, dear owners: Jason Marquis, at least, remains a tried and true time bomb, ticking onward to mid-summer and his subsequent devolution into a pumpkin with arms.

I remain bewildered, though. How does a man go from essentially league-average as a reliever one year (99 ERA+) to stud starter the next (136 ERA+)? Maybe there's more to all that running up Camelback Mountain than we thought.

(Aside: One of my uncles lives in Phoenix, and for many years hiked the mountain regularly without water, no matter the blazing temperature. He still does his hikes, though less frequently and, so I'm told, with fluids in tow, after years of insistence from my aunt. Why he would need any encouragement to re-hydrate in such heat remains a mystery, though, much like how he always returned home alive, not shriveled.)

Or maybe it's something else. Dempster's not throwing more strikes, averaging, as he did last season, 1.7 strikes per ball. His strikeouts are down by more than two per nine innings to 5.35, and his walks are up half a walk per game to 4.62. Somehow, though, he's keeping batters from hits and home runs at, for his career, unprecedented rates. The key, I think, is this: more than 55 percent of all balls he allows in play are groundballs, almost matching the rate from his stellar 33-save 2005 season and up from 51 and 47 percent in 2006 and 2007, respectively.

That's an encouraging trend, if one that's highly dependent on the Cubs' infield defense. And from what I've seen, Dempster's been keeping the ball down -- it's unsurprising, then, that he's getting more grounders -- to great success.

I'll end with a question: Do any of you, dearest readers, have access to, or know where to find, Dempster's Pitch F/X data from last season? I'm curious to see the differences between this season and last.