This could all change, of course. In 2009, Boston won the first eight games of the season series against New York. But the Yankees, on their way to a World Series championship, went 9-1 the rest of the way against the Red Sox.
For the moment, though, the 2011 Red Sox have been able to beat the Yankees on a regular basis, and on the basis of beating the Yankees when they were in serious need of victory.
The Red Sox began the season, unthinkably, at 0-6. They then took two of three from the Yankees, proving conclusively that they had a collective pulse. The Red Sox came to Yankee Stadium in mid-May, three games under .500. They repaired that situation with a three-game sweep that served to send them on their way to what has become a 17-6 tear.
One game behind the Yankees in the standings, the Sox came back to the Bronx on Tuesday and took the first game of this series. Thus, they became the first visiting team to win four consecutive games at new Yankee Stadium.
Before the game, it was instructive how each manager responded to a question about the importance of this series.
"It's an important series for us," Yankees manager Joe Girardi said. "We have not played particularly well against the Red sox in the last two series."
Red Sox manager Terry Francona, meanwhile, was in a position to say that this series was no more or less important than the series that preceded it or the one that would follow it.
"Until they give you one-and-a-half for a win, they're the same," Francona said.
A 6-1 series edge for anybody would be the exception rather than the rule in the recent history of this series. In the nine regular seasons before this one, the Yankees have an 86-81 edge. Throw in the season's early results and it's all tied at 87-87. During those nine seasons, neither team had an edge larger than 11-8 in a single-season series.
There is plenty of time for the Yankees to turn this season's competition around, but for now, the rivalry has been a tonic for the Sox, who have greeted these occasions with a blend of solid play and impeccable timing.
On Tuesday night, the Red Sox manhandled Yankees starter Freddy Garcia in what was by far his worst start of this season -- four earned runs over 1 2/3 innings. Red Sox starter Jon Lester, well off his best form in recent outings, still wasn't at his peak, but he battled through six innings and emerged with an 8-1 career record against the Yankees. Even better in a way, Lester is 6-1 in New York and has won his last five starts against the Yankees.
"Obviously it's nice," Lester said of that mark. He added that he enjoyed the atmosphere at Yankee Stadium, just as he enjoyed the atmosphere at Fenway Park. He gave due praise to the Yankees' lineup, adding that a pitcher facing the Yankees knew how difficult it was to go deep into the game. He was modest and deferential about the whole thing, but at the end he was still 8-1 lifetime against the Yankees.
All of this will be a mere footnote to the 2011 season if the Yankees finish ahead of the Red Sox in the AL East and/or outdo them in the postseason. But for the moment, the Red Sox have a 6-1 season record against the Yankees, a four-game winning streak in the Bronx, and a very good feeling about their half of this rivalry and the direction of their season.