Nothing will drive a baseball fan mad quicker than a team that doesn’t hit in the clutch. There is nothing worse, and no amount of knowledge will make it better.

A perfectly rational person, fully aware that performance in the clutch has nothing to do with character and that it has more than a bit to do with luck, will still be driven to throw heavy objects when his team’s lineup, from the top to the bottom, performs feats of wonder of the kind the Mets have this season. Every called third strike, every rally-killing double play, and every weak flare to short drives up the blood pressure, induces both hooting and hollering, and makes every game a slow act of torture.

The numbers you can dredge up to prove the point are just horrifying. Take the Mets’ batting averages with runners in scoring position and two outs. Statistically, they’re meaningless, but they serve as a good proxy for misery and frustration, as nothing is more maddening than repeated, consistent failure in those tantalizing moments when runners are on and the batter must either do something about it or end the inning. As a team, the Mets aren’t doing horribly in this situation — their .223 average is pretty bad, but then fully half of National League teams are batting .227 or less, and the league average is .238. Individually, though, their best hitters appall. Jose Reyes, as of the start of yesterday’s game, was batting .218 with runners in scoring position and two outs. David Wright was batting .196, Paul Lo Duca .186, Carlos Delgado .167, and Carlos Beltran .111. It’s embarrassing.

Worst of all is the sort of nagging kink this kind of play puts in the rhythm of the season. Sometimes — think of the 1999 Mets — a team is going really well and gets every key knock they need, seemingly without fail. Exuberance is in the air; the team swaggers, fans exult, and days pass brilliantly. When they miss every opportunity without fail, the team is glum and fans become pessimists, and big hits like Chip Ambres’s game-winning single in the 10th inning yesterday can even irritate by their contrast with the usual shoddiness.

All of this may be so, but it’s still important not to mistake what is essentially an aesthetic complaint for a grave problem. Over time, nearly without exception, how well a team performs in the clutch is a function of how well its players do, and the players’ performance is just a function of how good they are. The teamwide funk, no matter how real it seems, is an illusion — prosaic as it is, the truth is that the Mets’ problems are not the result of their mysterious clutch woes, but rather of a few key positions being manned by armies of green rookies and undead minor league veterans for long stretches of the year.

The average National League team this year has driven in 28.9% of the runners who reach base. (This figure doesn’t count home runs, because while a home run may count as a run batted in, it’s not really what we’re talking about when we bemoan failures to get in the runners who have gotten on and gotten over.) The Mets have driven in 25.2%. That’s pretty bad — if the Mets had driven in an average proportion of their baserunners up until now, they’d have scored about 50 more runs on the season. Using the rule of thumb that 10 runs are worth about a win, a look at the standings will show that this is the difference between contending for the best record in the league and trying to outpace a flawed Atlanta team.

Still, if we’re wondering where those 50 runs went, there are better places to look. Delgado has been worth about 10 fewer runs than Scott Hatteberg this season. The corner outfield positions have — occasional fits of usefulness from Shawn Green aside — been near black holes, as the bench has been. It would be nice if the Mets were doing better with the chips down, of course, but it would be even nicer if various veterans were healthy and performing up to their usual standards. If they were, and the Mets were just hitting as well as the average team in the clutch, this would be the best team in baseball.

What matters, though, is not what they could have done, but rather the rest of the season, and that’s a good thing for both the Mets and heavily irritated fans. Just in the course of things, a player or team will, after doing something exceptionally badly for awhile, usually start improving at it. The lineup isn’t about to become eight-deep in David Ortiz impostors; things don’t work that way. But if they simply start hitting in the clutch about as well as the next team — and this weekend’s series showed some signs of them threatening to start doing at least that much — they’ll be a wrecking ball. If they just keep on the way they’ve been playing, they’ll still be on pace to win the division and head into October with strong pitching, a great defense, and a pile of excellent hitters. Misery and all, it’s at least something.

tmarchman@nysun.com