"Re-projecting" is something I would occasionally do early in the season at my old blog (at least in 2009; I don't remember whether I did it again in 2010). The basic idea is this: we know, or should know, that no matter how convincing a player's performance is after 18 or 20 or 30 games, his performance over the last several years -- adjusted for age, park, etc., as the various projection systems do -- tell us a lot more than these first few weeks do about how he's likely to perform over the next 120-plus games.
But the other thing about these early games, of course, is that they still count. Any given player is likely to match his projection from here on out, but these first few weeks still happened, and will impact his overall numbers. So what I did, and what I'm going to do again with one player right now, is look at one player with a particularly surprising start to the season, apply the projections to the rest of the season, and take a look at where his end-of-the-year numbers might end up.
The system I'm going to continue using is PECOTA -- not because I think it's better than the rest, but because I think they're all pretty fungible, and Baseball Prospectus puts nice descriptive words alongside their numbers (and, now, because I know and like a bunch of these BPro guys).
And the player is Jose Bautista.
After a phenomenal 2010 in which his majors-leading 54 homers was nearly three and a half times his previous career high, this was a particularly tough assignment for PECOTA, so maybe this isn't fair, but what PECOTA saw was this: .253/.357/.479, 25 HR, 73 R, 74 RBI, 73 BB, 102 K. That's in only 548 PA, though, which reflects his part-time usage prior to 2010. If we adjust to 650 PA, he gets 30 HR, 88 RBI, 87 R, 87 BB, and 121 strikeouts.
Of course, he's come out of the gate even better than he ever looked in 2010 (and he had some great months, just not this great). Even after a 1-for-4 yesterday (which did include a double, a walk and 2 RBIs), Bautista's hitting .356/.515/.767, with 8 homers, 13 RBI, 24 walks and 16 Ks. Through Tuesday -- and, as far as I can tell, through Wednesday -- he led the American League in batting average, on-base percentage, slugging percentage, walks and home runs, and runs scored (though, curiously, he's still off the top ten in RBI).
At this point, it seems likely that he's made some significant improvements and simply isn't the same hitter he was when he put up most of the numbers PECOTA is relying on. So realistically, he's probably better than this...but he might also just be having a good eight or so months of baseball. So if he just matches his PECOTA projection from here on out and totals 650 PA*, here's what his final line might look like:
.267/.375/.505, 33 HR, 87 RBI, 95 R, 96 BB, 118 K
*I actually just added his full projection on to his current numbers, since I'm adding 102 PA to the projection and he has 97. I didn't think it was worth adding the extra 0.7% in.
So really, given his 2010 and his start to 2011, that line would be pretty disappointing. It's also still a significant boost over his original projection, though, and if you assume that he gets hurt and does end up with just 548 PA, the rate stats start to look a lot better. I think it's likely that Bautista ends up a lot better than that, and maybe continues to be one of the best hitters in the league for the next couple years, even if he doesn't lead the league in all those categories.
It's a pretty silly exercise, really, but the point is that Bautista may really not be any better than his projections, but it's already very likely that his 2011 numbers will be.