The joys of National League baseball are never more apparent than when a pitcher steps into the batter’s box, grabs the top of his helmet, chokes up his bat, and peers out at the mound, an expression of steely resolve or bewilderment written across his face.

Of late, New York has been blessed with some of the most ridiculous sights ever seen by baseball fans. For years, Al Leiter, a career .085 hitter whose average was inflated by a flukish .185 mark in 2002, gamely swatted at almost anything that came his way, looking less like a major league baseball player than I would were I faced with the specter of John Smoltz; a triple he somehow smacked in 2001 is one of the best things I’ve ever seen on a diamond. Pedro Martinez, his successor as ace of the Mets staff, is at least as inept.

Fans in the Midwest, meanwhile, have enjoyed watching Cubs ace Carlos Zambrano, a hulking beast who hits without batting gloves, is good for a home run or two each year, and runs the bases like he thinks he’s Rickey Henderson. They’ve also been treated to the Cardinals’ Jason Marquis, who actually gets used as a pinch-hitter once in a while and has hit .302 since 2004. And, somewhat unbelievably, they’ve seen Bronson “Brandon” Arroyo, who looks like a clubhouse boy, slug two home runs off the Cubs already this year. Rest assured that one day, as his grandchildren ask him to name the fondest memory of his major league career, Brandon will have to think awhile before picking between the 2004 Red Sox’ World Series win and the glorious day when he ranked among the top 10 in the N.L. in home runs.

The difference between the very best hitting pitchers in the game, like Zambrano and Marquis, and the worst, like Martinez or Cincinnati’s Aaron Harang, is pretty big – about 10 to 15 runs over the course of a season, which is similar to the difference between the best baserunners in the league and the worst. It’s worth wondering: If a team really focused on improving its pitchers’ hitting skills, how much difference would that make?

National League pitchers hit .147 BA/.179 OBA/.188 SLG last year, so any pitcher who can hit anything at all definitely gives his team an edge on the competition. There are a few mitigating factors, though. The first is that pitchers just don’t hit all that often – collectively they account for about 5,000 at-bats a year, about 30% as many as right fielders do. Most teams give only about 350 at-bats a year to pitchers.

Even if you have excellent hitting pitchers on your staff, they just don’t have that many chances to affect games with the bat. Their impact is more likely to show up in starters being able to stay in games a little bit longer, pinch hitters being saved for crucial late-inning at-bats, and whatnot. Over the course of a season these are good things, but not of immense importance.

Second, and more important, the spread between most pitchers just isn’t that big. The difference outlined above is between the absolute best and the absolute worst in the game; the difference between a normal, good-hitting pitcher and a normal, bad-hitting one is more like three or four runs a year, nothing that’s going to move the standings much one way or the other. All else being equal,a team with a staff full of pitchers handling the bat reasonably well might squeeze out a win or two more than a team full of pitchers waving feebly at 75-mph fastballs 8 inches off the plate; but then again, all else is never equal.

Finally, even the best hitting pitchers don’t really hit all that well. Zambrano hit .300/.300/.463 last year, more or less equivalent to Doug Mientkiewicz’s .240/.322/.407 when park effects and such are taken into account. Marquis hit .310/.326/.460, not much more impressive than Ramon Castro’s .244/.321/.435. Relative to their peers, these two and the likes of Dontrelle

Willis and Livan Hernandez are contributors, but they don’t confer a sizable advantage.

Of course, having a lot of pitchers who can hit with some confidence is a good thing, just the same way it’s better to be smart and efficient on the basepaths, rather than stupid and reckless. A team that wrings the last bit of talent out of every player on its roster can add several wins over a team just as good at the basics of pitching, catching, and hitting the baseball but more indifferent in the subtler aspects of the game.

Incidentally, the inability of pitchers to hit isn’t all that mysterious. The National League is the only professional league that doesn’t use the designated hitter rule. Most teams feel it’s far more important to keep their prospects safe and focused on their pitching than to gain a marginal and possibly negligible advantage by having them work seriously on their hitting.

This is also good evidence of the way competitiveness has increased over time in baseball. In high school, the best pitcher almost always plays shortstop and hits cleanup, because he can dominate through athleticism. By the time that player reaches the majors, he’ll need to specialize, because physical skill isn’t enough at that level. Similarly, the fact that pitchers used to hit much better compared to the league average (in 1972, for instance, they hit a robust .149/.191/.188) is, to my mind, good evidence that the game has gotten more difficult. In ye olden days, teams could afford to have their pitchers focus on their at-bats; these days, the game’s just too hard to afford that luxury.

This is, in all, a perfectly good thing. No one cares that Pedro Martinez can’t hit. Carlos Zambrano isn’t considered an ace because he can. And Bronson Arroyo won’t get a raise for striking fear into the heart of the Cubs’ inept pitchers. At least he’ll have his memories.

tmarchman@nysun.com