MLB

Yankees live — and die — by home run

Curtis Granderson embodied the character of the 2011 Yankees offense last night.

For two at-bats and two pitches, Granderson could not have looked more incompetent against Mets lefty Chris Capuano. In fact, he looked a lot like the old, inept Granderson against a southpaw, striking out in his first two at-bats, flailing behind 0-2 in his third.

And then Capuano tried to throw another slider to sweep away from Granderson and, boom. “I went from being dominated to putting one in play,” Granderson said.

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Of course, these days when the Yankees put one in play, they very often knock it out of play, as Granderson did by launching into the right-field seats.

That vignette summed up this Yankees lineup: From hopeless to homer.

These Yankees, in fact, are going to force us all to answer big, philosophical questions about baseball, notably these two:

1. Can a team be too reliant on homers?

2. Can a team lead the American League in runs and still have an underperforming offense?

The Yankees have eight runs in two Subway Series games and — no surprise — all but one are homer derived. On Friday, the Mets held the Yankees to one homer and, thus, one run and won 2-1. Yesterday, the Yankees produced four homers, including Granderson’s leading off the sixth, and topped the Mets 7-3.

The Yankees had three singles, did not draw a walk and failed to get a runner into scoring position — beyond jogging on a homer —until the eighth, when they already had built a 6-2 lead thanks to homers by Russell Martin, Mark Teixeira, Granderson and Alex Rodriguez.

They now have an AL-high 226 runs, and 52.2 percent of those have come via homers. The record is 53.1 percent by the 2010 Blue Jays.

On days when the ball is flying, especially in their launching-pad park, they play with an imposing muscle. But there have been so many days this year when their power was either limited or shut off, and suddenly this attack goes flaccid, hungry for a sac fly, a cheap single.

Manager Joe Girardi described the offense as “up and down” and A-Rod as “good and bad.” The attack has been so hit and miss that when Yankees media relations head Jason Zillo told Rodriguez yesterday the team actually led the AL in runs, “I didn’t believe it,” A-Rod said.

Going into yesterday, the Yankees did not have a player in the top 64 in batting average with runners in scoring position (minimum 25 plate appearances). But they had four players in the bottom 52: Jorge Posada (.160), Nick Swisher (.171) Rodriguez (.182) and Derek Jeter (.186).

“I think we’re a very good offense,” general manager Brian Cashman said. “We have not hit with runners in scoring position and that makes you look inadequate, but statistically that often turns around.”

Of course, this is more than just the clutch deficiency. Offense is down around the sport, so naturally the Yankees are down, too. More troubling for the Yankees, however, has been the dead spots in the lineup. Posada and Swisher are particularly troubling because the team has always benefited from having multiple, excellent switch-hitters who bedeviled the late-game maneuverability of opposing managers.

This is why the Carlos Beltran-to-the-Yankees engines rev: He is a switch-hitter who could DH rather than Posada or play right rather than Swisher. Of course, the Mets are not ready to surrender their season or Beltran yet.

So for now the Yankees will live — and die — with deep intentions. They have five players with eight or more homers (Martin, Rodriguez, Teixeira, Granderson and Robinson Cano), and no other team has more than three. They have 70 homers in all, 18 more than the second-place Reds.

The Yankees are doing this with almost no power from their corner outfielders, Swisher and Brett Gardner, and no power since April from Posada.

Are they giving away too many at-bats, failing to honor their recent heritage of weakening starters with the long count and bushels of walks?

It is a long season, just beyond the quarter-pole now. Maybe some answers reside with the weather warming or Jesus Montero being promoted or the acquisition of a veteran stick such as Beltran.

For now, however, they are a long story and in yesterday’s chapter they again went from hopeless to homer, making their problems going, going, gone.

joel.sherman@nypost.com