There was a great ballgame buried beneath the last few innings’ worth of inept relief pitching, sloppy defense, and unaccountably bad managing in last night’s slugfest between the Yankees and Red Sox. The game was supposed to have been a pitcher’s duel between Mike Mussina and Curt Schilling; what we saw from the two aces might ultimately decide this series.

The difference between the part of the strike zone where a hitter’s greatest strengths and greatest weaknesses lie can be smaller than a baseball. Sometimes, if the reports issued by private scouting bureaus using new technology are to be believed, they can be as small as a quarter. Greg Maddux, for one, can succeed against the best hitters in the world with raw stuff that wouldn’t interest a Division II coach because he understands this crucial fact and has the discipline to exploit it.

Mussina and Schilling, like Maddux, are among baseball’s best at putting the ball where the hitter can’t reach it while making it look as if they can’t miss it. This is why, with fastballs nowhere near as hard as they once were, with sliders and split-fingered fastballs that break and drop nowhere near so crisply as they once did, these two were starting in the first game of the American League Championship Series last night.

One succeeded and the other failed because of something equally necessary: health.

Schilling went into last night’s game with an ankle hurting so badly it was not only directly injected with anesthetics, as it has been for much of the season, but also held motionless by a brace. The pitching coach Tom House says that a difference of 1/8-inch in where the pitcher releases the ball can alter by 6 inches or more where the ball arrives when it reaches the batter.

It’s easy to understand, then, why Schilling had almost no control over his pitches last night, why he abandoned a split fingered pitch that wasn’t splitting for a slider that wasn’t sliding, and why the Yankees were able to smack his pitches like golfers driving off a tee. (It had nothing to do with his obnoxious braggadocio.)

The legs are the most important part of a pitcher’s delivery, the part from which he generates his power and from which he derives his stability. Coming down on an immobile ankle, Schilling’s mechanics altered from those he’s been honing his entire life.

So there was no question that the Yankees weren’t going to see Schilling at his best last night. The real question is why he wasn’t taken out of the game sooner than he was. It was immediately and dramatically apparent when he gave up three two-out hits in the first inning that something was seriously wrong.

The way he tied and retied his shoe, his pained grimaces, and most of all the soft break on all his pitches and his lessened velocity gave every indication that, unable to drive off his right foot, Schilling had nothing. It was so apparent that Jorge Posada, of all people, made an aborted attempt to bunt towards the pitcher’s mound for a base hit with two outs in the bottom of the first inning.

Schilling should have been taken out, and if manager Terry Francona didn’t want to take his ace out, he should have taken himself out.

Mussina, meanwhile, once again proved that he is still an ace pitcher. He throws something like eight pitches; all except his change-up are very good, and as his velocity has de creased he’s compensated with increased command. Combine this with a fine and precise knowledge not only of hitters’ general weaknesses but of the more precise ones betrayed on any given night by the way a hitter positions himself at the plate and you have the Hall of Famer we saw last night.

A pitcher can never plan to have what Mussina had last night – pinpoint location and control of all of his pitches. What he can have is a game plan, and Mussina’s was incredible.

The first time through the batting order Mussina was, as the cliche has it, hitting his spots. That’s more important than it sounds. David Ortiz, according to Inside Edge scouting reports posted on the Boston Globe’s Web site, hits .382 middlein, but only .135 up and in and .232 down and in. To get him out, you have to come inside; miss your release point by that 1/8-inch Tom House talks about, and you’ve given up a home run. Mussina got him out down and in, and he did the same thing to Ortiz’s teammates through the first three innings, in which he gave up one hard hit ball: He mixed his pitches, relying particularly on a devastating knuckle-curve, and hit the parts of the strike zone where their weaknesses lay nearest their strengths.

As the game wore on, Mussina started pitching to his oppponents’ strengths. A sequence to Johnny Damon in the bottom of the sixth shows it perfectly: He twice went with fastballs up and away, where Damon (again according to Inside Edge) hits .393; he then went down and in, where Damon hits .333, with the knuckle-curve, up and away again. He then struck him out with another knuckle-curve that broke out of the strike zone over the middle of the plate, passing through a zone where Damon hits .303.Mussina employed a similar strategy against Mark Bellhorn, and gave up the first base runner of the game only when he threw a fastball middle-away, where the Sox second baseman hits .143.

If he had come out with nothing last night, Mussina probably would have kept the Red Sox down. As it was, he was devastating into the seventh, and there’s no reason to think that had Schilling been healthy he would have done anything less. A few days of rest for his ankle might do him a world of good. This is still the closest of series.