Not long ago, their lead was oversized, roomy, comfortable.
Now, with just over a week remaining in the regular season, it's suddenly snug, tight, constricting.
The talk that they are creating an unwanted sequel to 1978 has grown from background chatter to white noise they can't completely tune out.
The Red Sox, of course, aren't concerned with history. There are plenty of players on their roster who weren't yet born when the Yankees overtook Boston 29 years ago this fall and many more still who don't care about the past.
These Sox are interested only in the present, which admittedly doesn't look good. Not after being swept in Toronto, extending their skid to four straight losses and five defeats in the past six games.
Most of all, there's the matter of what fictional Yankees employee George Costanza of "Seinfeld" fame would call "shrinkage." The Boston lead in the AL East over the second-place Yanks was seven games less than three weeks ago, but has shriveled to a mere game and a half -- and only one in the loss column.
How did the Red Sox get themselves in this predicament?
Start at the end and work backward. The bullpen, so airtight for the first four months of the season, has imploded. Through their first 116 games, the Sox lost just twice in games they led after seven innings, but they've done that twice in the past six games.
Over the past eight games, the bullpen's ERA is 6.20. Over the past 19 games, the bullpen's ERA is 4.98.
Eric Gagne, obtained at the July 31 trade deadline to augment the setup crew, has been a spectacular failure, compiling a 9.00 ERA in 15 appearances. Hideki Okajima, a revelation through the middle of August, has been shut down because of fatigue and has allowed multiple runs in three of his past seven outings -- something he didn't do once in his first 57 major league appearances.
Even nonpareil closer Jonathan Papelbon has dipped. Papelbon didn't allow an inherited run until last Friday, but he has given up five in his past two outings.
Wednesday night, Papelbon labeled the bullpen downturn "hard to believe because we have been so good. We've got to keep grinding it out. Unfortunately for us, the bullpen is going through a tough time at a tough time in the season."
The offense hasn't been much better. Six times in the past nine games, the Sox have been limited to three runs or fewer. Rookie Jacoby Ellsbury has been a late-season spark, hitting safely in 16 of his past 17 games, but he can't replace Manny Ramirez (oblique strain), whose absence this month has thinned out the lineup.
David Ortiz is just 1-for-14 with seven strikeouts in the past four games in part because his balky right knee is killing him and restricting him at the plate. He needs a day off, but with the offense sputtering, the Sox haven't been able to give him one.
Through it all, the Red Sox, who for all their fumbling need to win only three games out of their final nine to clinch a postseason spot, have been trying to rest their starting pitchers and set up a semblance of a playoff rotation.
That sets up 19-game winner Josh Beckett as the playoff opener, to be followed by either Matsuzaka or Schilling, depending on the final week and the opponent.
We have to prove what kind of team we are. ... Everyone's got to take a reliever's mentality -- shake it off. It's over with. We lost; we can't change it.
--Red Sox reliever Mike Timlin
The Sox learned the hard way about the importance of setting up the rotation for October. In 2005, they didn't clinch a playoff berth until the last day of the season and had to open the AL Division Series with Matt Clement, arguably their fifth-best starter. Clement withered in Game 1 and the Sox never recovered; they were steamrolled by the Chicago White Sox in three straight games
The rotation machinations have led to the suggestion that the Sox are getting ahead of themselves, since they haven't clinched a playoff spot, much less the division.
But that's not how manager Terry Francona sees it.
"First place means a lot," Francona said this week, "because that's what we set as our goal at the beginning of the season. But it doesn't mean much [when it comes to winning] a World Series."
That's tough to argue, since home-field advantage hasn't translated into much of a postseason advantage in recent years. As for the wild card, baseball had a stretch in 2002-04 in which the World Series champions didn't win their own division.
A new perk this postseason for the team with the league's best record is being able to choose which division series playoff schedule it wants (either Game 1, off day, Game 2 or Game 1, Game 2 and then the off day). What of this advantage for the team with the most wins?
"I'm more concerned with how we play rather [than] where and when," Francona said succinctly.
Still, there's work to be done and a turnaround to be executed for a team that has held onto first place every day since April 18.
"This is when a team has to pull together," said shortstop Julio Lugo after the Sox were swept by Toronto. "From now on, you're going to see who's who. That's it."
"We have to prove what kind of team we are," added veteran reliever Mike Timlin. "We need to have momentum going into the playoffs. Every team does. Everyone's got to take a reliever's mentality -- shake it off. It's over with. We lost; we can't change it. We'll regroup and play the best we can against Tampa. That's all we can do."
Sean McAdam of The Providence (R.I.) Journal covers baseball for ESPN.com.