The Pirates have the worst record in baseball in one-run games, and the Washington Nationals have one of the best.

Is the reason a better manager? A better closer? A better team?

Before we get to those possibilities, let's not discount that crucial aspect of baseball that too few fans ever want to acknowledge.

Luck.

Eddie Epstein, a former front-office executive for the Orioles and Padres, wrote an essay for ESPN.com some years ago that looked at every team's record in one-run games since 1900. He found:

Very good teams had a worse record in one-run games than their overall record.

The poorest teams had a better record in one-run games than their overall record.

On good teams and bad, records in one-run games are generally closer to .500 than the overall record.

"When a game is close,'' Epstein wrote, "the final outcome becomes more dependant on luck than it does when the game is not close."

Think about it. If the Pirates get the out call at first base in the Bronx, the Pirates win, 5-4, against the Yankees. If Johnny Damon hits his bouncing grounder another couple of feet to the right or left, or Jack Wilson bounces on home plate instead of over it, maybe the Red Sox don't win 6-5 in Boston.

Fans don't want to hear that because it reeks of excuse-making. The team's record is the team's record, and there's no going back. That's true, and noble. But Epstein's findings and recent Pirates history suggest that the Pirates' one-run record should begin to even out soon.

The Pirates went into last night's game with a 6-14 record in one-run games, an embarrassing .300 percentage. The Nationals were 17-7 in one-run games, a .708 percentage. Washington's eight-game advantage over the Pirates in the standings is almost entirely because of its supremacy in one-run games. Both teams have given up more runs than they've scored.

Bill James suggested a few years ago that a team can't win more than its share of one-run games consistently, but it might be possible to lose them. So I looked at the Pirates' record under manager Lloyd McClendon to see if that pattern is there. It's not.

The Pirates were much better at winning one-run games when they were worse. One could argue, I suppose, that McClendon has forgotten how to win such games, but his five-season record in these games is 99-111 for a .471 percentage. His overall record is 312-401, a .438 percentage. So Epstein's finding that records in one-run games lean toward .500 holds.

McClendon's record in tight games has been nearly the same as his overall record in each of the past two seasons. One more narrow loss in 2003 or one fewer in '04 and the differences would be only in the last digit. This season has been the anomaly. Had the Pirates been taking close ones at even last year's relatively poor rate, they would be a winning team today.

So what's been the problem?

The tempting answer is the closer, Jose Mesa. As Bob Smizik pointed out in his Sunday column, Mesa's record in protecting one-run leads and preserving ties has not been good. With his 4.38 ERA, that is no surprise. That's about a run every other inning, so in any given inning there's a 50-50 chance Mesa will give one up. Sure enough, Smizik found that the Pirates lost four of the eight games that Mesa entered with the Pirates ahead by a run or tied.

This year's best NL teams in one-run games, the Padres (15-5) and Nationals, have closers with exceptional strikeout-to-walk ratios. Trevor Hoffman tops the league's closers at 11.00 and Chad Cordero is sixth at 3.56. The teams with exceptional one-run records last year, the Padres and Dodgers, also had closers with great K/BB ratios (Hoffman at 6.63 and Eric Gagne at 5.18).

The Marlins (7-14 in one-run games) and Pirates, meantime, have Todd Jones at a modest 2.30 and Mesa at a miserable 1.43. The argument would end there had the White Sox not won so many one-run games (20-8) despite a closer, Dustin Hermanson, with a 1.55 ratio, barely ahead of Mesa's.

There are enough other exceptions to make the argument imperfect, so you are welcome to hope that Epstein's Law will take hold in the coming months in the form of bounces going the Pirates' way. But if the closer continues to walk nearly as many as he strikes out, lucky bounces could be the only hope.