One month ago, with the Yankees coming off a series loss at Boston that left them 7 1 /2 games ahead in the AL East, I wrote that the Red Sox were a better team than the Yankees, were more likely to win the World Series, and had a chance at winning the division.

As happens when sportswriters make predictions, I was quickly made to look the fool. By August 8, the Yankees were up by 10 games and the Red Sox were concerned more about their rapidly fading chance of winning the wild card than they were with catching the Yankees.

That’s all changed, of course. After the Yankees’ humiliating 22-0 loss last night, they are just 12-11 since August 7,during which time the Red Sox are on a 19-4 run. With Boston just 3 1 /2 games back and six games yet to be played between the two teams, the division is very much up for grabs.

While it’s easy to superimpose some mystical narrative on this turn of events having to do with the trade of Nomar Garciaparra improving clubhouse chemistry or the Red Sox “turning it on” in August, the truth is that they haven’t been playing all that much better lately than they have all season.

In August they scored 176 runs, 12 more than in July, when they went 14-12, and just three more than in May, when they went 16-14. The team’s 3.77 ERA in August was better than in July (4.67) and May (4.55),but not much better than in June, when they had a 4.13 ERA and went 11-14, and much worse than April’s 2.95.

All along, the Red Sox have been scoring and preventing runs well enough to be winning more than the Yankees. Going into yesterday’s games they had scored 27 more runs than the Yankees and allowed 55 fewer. Using the rule of thumb that a difference of 10 runs usually equals a game in the standings, one would expect the Red Sox to be leading the AL East by four games.

It’s no mystery why the Sox have been so hot: Despite playing no better or worse than they have all season, they’ve been playing with good luck, just as they were playing with bad luck for most of the year. Key base hits are falling in, double plays are made at the right times, and every substitution Terry Francona makes seems to be the right one. That there is a race for the division is less a result of a Yankee collapse or a Red Sox resurgence than the result of their respective records falling in line with how good the two teams actually are.

So, with that said – do the Sox have any chance of winning the division?

Statistically they do, but it’s a small chance. Part of the reason is that the Sox will face opposition with a .511 winning percentage over the next month, while the Yankees’ opponents’ are at .492. It’s a small difference, but the Sox will need any edge they can get.

The biggest factor, of course, will be the six games the two teams play against each other from September 17-26. Projecting the rotations three weeks out, the pitching matchups don’t look good for Boston. The first series, played in the Bronx, matches Kevin Brown against Derek Lowe, Pedro Martinez against Mike Mussina, and Javier Vazquez against Tim Wakefield. One week later in Boston, Mussina faces Wakefield, Vazquez goes against Curt Schilling, and Orlando Hernandez meets Bronson Arroyo.

For the Sox to win the division, they’ll probably have to win at least four of these games, and they look to have a decisive advantage in only one, the September 18 matchup of Martinez and Mussina. The Yankees, meanwhile, have a clear edge in at least three, and possibly four of these games.

Attention to details like this is a lot of what keeps the Yankees on top even when the Red Sox are actually, in some abstract sense, the better team. Can you imagine Joe Torre lining up his rotation so that Jon Lieber would be in line to start two of these six crucial games? Of course not; but that’s exactly what Francona has done by leaving Wakefield in position to start two games – as many as Martinez and Schilling combined.

We’ll see if the Red Sox jigger their rotation, but in a month during which they need every advantage they can get, they’ve stripped themselves of the biggest one they have.