OK, yes, we concede it: The rivalry between the Boston Red Sox and the New York Yankees is the keenest in baseball, and has been for at least a decade. Nothing comes close.

Whatever pretensions the Dodgers and Giants or Cardinals and Cubs or anyone else might have had to being Beisbol Rivalry Numero Uno … yes, over with.

When the Yankees and Red Sox play, it appears that everything grinds to a halt in the Northeast Corridor.

Including the clocks.

This ia very long rivalry. And not always in a good way.

To wit:

These teams take forever to achieve a result.

Consider these eyeball-numbing numbers:

–Average time of game for the 10 Red Sox-Yankees Games played so far this season? Three hours and 54 minutes.

–In five of the 10 games played, so far, the home team didn’t even bat in the ninth inning. That is, they were 8 1/2-inning games. So, did that make them nice and snappy? Uh, no. Average time of game for those five: A sluggish 3:16.

–Even if we take out the two extra-inning games played by these clubs so far (including last night’s 5 hour and 33 minute, 15-inning marathon, the other eight matchups clock in at an average of 3:38.

The fastest game these two teams have managed, in 10 tries? 3 hours and 4 minutes in a 7-0 Boston victory that ended after the top half of the ninth. So, yes, even in a lopsided game in which the home team didn’t hit in the last half of the ninth, they needed more than three hours to achieve a result.

This is not good for the game. It might not even be good for the rivalry.

You don’t just watch the Yankees and Red Sox. You endure it. You set aside the time normally associated with a Super Bowl. Or a college football bowl game. And you do it for three or four consecutive days.

Why do these games last so long? Because they are fraught with meaning.

The Yankees and Red Sox have won six of the last 13 World Series — and have played in two more. That is, eight of the last 13 World Series have featured the Red Sox or Yankees, and they get there at the other guy’s expense.

But … still …

These games are just too long. And they get that way by a long, running tab of small and not-s0-small delays.

Changes of pitchers (on average, 9.2 pitchers per meeting this season) … meetings on the mound … pitchers throwing over to first base … batters digging in and then getting out … pitchers stepping off the rubber … catchers visiting the pitchers … requests for signs to be repeated … taking lots of pitches and long at-bats … lots of runs scored.

There have to be ways to hurry up this process. There are rules about how long a pitcher has to deliver a pitch (12 seconds, with no batters on base), but they are not enforced. There is absolutely no attempt to move along these games. Because they’re too important, see?

But what we are getting is 18 meetings a year between these two that rival Test Cricket for duration. I mean, if you can run the Boston Marathon in 2 hours and 8 minutes, if the epic movie Ben-Hur lasts “only” 3 hours and 32 minutes … why can’t Boston and New York play ball in less than 3 hours?

This isn’t just a Bosox-Yanks issue. Ballgames are getting longer all over MLB; the average is around 3 hours now — when it was less than 2 hours 60 years ago. (And, yes, they went nine innings back then, too.) But it seems most egregious when these two get together and slow dance … forever.

Frankly, I’m glad I’m not a fan of either one of these teams. I like looking at the results, and the boxscores … but I would hate to see these extra-long sausages being made. Just too gruesome and too grueling.