No matter how much one wishes it weren’t so, there’s no way to avoid seeing that the single biggest reason the Mets aren’t going to be playing next month is Carlos Beltran. His .271 BA/.336 OBA/.424 SLG line is simply not what the Mets paid for, and far below even the most pessimistic expectations for him. It’s not at all an exaggeration to suggest that the difference between what everyone thought he would do and what he’s done is the difference between playing golf and playing for the pennant.

At this point, it’s probably fair to invoke the dread name of Bobby Bonilla in comparison. Has Beltran been worse, relative to expectations, than Bonilla was in his legendarily disastrous 1992 campaign?

Two caveats should apply. The more important is that, excepting bizarre claims about how it’s alright for him to bunt in RBI situations because he doesn’t really care what Willie Randolph thinks, Beltran has comported himself with decency. His willingness to play through serious injuries and his refusal to come unglued in public over the boos he’s hearing make a stark contrast to Bonilla, who spent 1992 threatening to beat writers up, claiming he wasn’t paid to hit home runs, and calling the press box to complain about scoring decisions. Beltran’s acted like someone getting paid $17 million, while Bonilla acted like a monumental jackass, and that does make a difference.

The other caveat actually works in Bonilla’s favor, and it’s simply that he, unlike Beltran, was held to unreasonable expectations. There was every reason after last year to think that Beltran had truly become one of the very best players in baseball, and he was still paid at a level below that reached by Alex Rodriguez and Manny Ramirez. Bonilla was a very good player who everyone at the time thought would continue to be one, and was made the highest-paid player in the game because the Mets were run by crazed lunatics.

With that said, the facts are unavoidable: Beltran has been a bigger bust than Bobby Bo.

To measure this by some objective standard, I first arrived at a projection for each player based on their statistics in the three years before signing their Mets mega-deals. This isn’t very difficult; all you have to do is weigh their statistics so that the most recent year counts three times, the next-most recent year counts twice, and the third-most recent year counts once, then divide by six. Add in a slight adjustment for park effects, and you have a reasonably accurate projection.

So, by this method, here is what the Mets should have expected out of Bonilla in 1992, followed by what he actually did:

Pretty dire stuff. The Mets could have expected an OPS of .880 from Bonilla; they got .780. By that measure, and ignoring his injuries and defense, his production was about 11% below expectations.

Truth told, though, Beltran’s been worse. Check out what the Mets were expecting, compared with what they’ve received. (The 2005 numbers are what he’s on pace for.)

Entering the season, a conservative estimate would have been that Beltran would be good for a .853 OPS; he’s come in at .716, which is 16% below what the Mets thought they were paying for. Granting that Beltran has been healthier than Bonilla was, that he hasn’t embarrassed the franchise, and that he’s been a very good center fielder while Bonilla was a very good right fielder (yes he was, skeptics) in his first season as a Met, he’s been worse than Bonilla was, both absolutely and in terms of relative expectations.

This is a disaster for the Mets; rich as they are, they can’t afford to pay an average center fielder like a franchise player and hope to compete for the pennant year after year. My operating assumption has been that Beltran would snap out of it at some point and start showing he’s the player we saw before this year, but it just isn’t happening. He has hit .320 this month – but he’s also hit all of one home run, along with indulging in Almoaresque small-ball antics. These are not encouraging signs.

What can the Mets do? Nothing. There are quite a few teams that would love to pencil in Beltran as their center fielder next year; the only thing to do is hope a winter of rest and relaxation will put him in form to dominate again, and hope we don’t see him playing cards with Rickey Henderson as the Mets lose a playoff series in 2012.