MLB

ROTATION DEBATE NO LONGER SWINGS IN BOSTON’S FAVOR

THIS was early in the season when the rotation was devastated, and the Yankees were starting every Tom, Dick and Karstens they could unearth.

That was the storyline, the Yankees’ rotation. The youth. The inexperience. The volume needed. The Yankees started rookies in 16 of their opening 30 games, including Jeff Karstens and Chase Wright in the first renewal of The Rivalry this season, a mid-April three-game set at Fenway Park.

That series is best remembered for Joe Torre breaking his vow to keep Mariano Rivera out of the eighth inning in the opener and Wright surrendering homers to four consecutive batters in the finale. The Red Sox swept that series, clearly establishing themselves as AL East frontrunners.

But re-examine that series now. Take a deeper look. Notice that while the Yankees were foraging for starters in Scranton/Wilkes-Barre and Trenton, the Red Sox used their front three of Curt Schilling, Josh Beckett and Daisuke Matsuzaka. And you know what? The Yankees hit them all well. And that has held true throughout this season.

The Red Sox have dominated the AL East this year behind a rotation that might produce both a Cy Young winner (Beckett) and a Rookie of the Year (Matsuzaka). But that rotation has not been effective against the Yankees. And now you may have this legitimate question: Do the Red Sox even have a better rotation than the Yankees?

The Red Sox again are sending out Matsuzaka, Beckett and Schilling for the three-game series this weekend, just like they did last month in the Bronx. The Yankees swept that series behind superior starts from Andy Pettitte, Roger Clemens and Chien-Ming Wang. Health permitting with Clemens, the Yanks will deploy the same three starters this weekend. It is possible, if both teams advance to an ALCS, you are also looking at the matchups for the first three games.

Therefore, the Red Sox trio could really use this weekend to establish an ability to pitch well against the Yanks. Matsuzaka is 2-1 against the Yanks this year, but has a 6.98 ERA. And in his last five starts overall, Matsuzaka is 1-4 with a 9.57 ERA. It may be that he is wearing down under the more demanding North American season.

Beckett has pitched extremely well against just about everyone, but is 1-1 with a 5.49 ERA against the Yanks. Schilling is 0-2 with a 5.76 ERA against the Yanks this year, and is trying to come to grips – similarly to Mike Mussina – on how to adapt with a fastball in the 87-89 mph range rather than in the 90s.

Beyond the main three, Tim Wakefield, who used to own the Yanks, is 0-3 with a 10.93 ERA against them this year. The Red Sox pitcher who has done the best overall job against the Yankees is No. 5 man Julian Tavarez, who is 2-0 with a 4.22 ERA in two starts. In the Red Sox’s first 15 games against the Yanks in 2007, they have one quality start, their last one when Schilling gave up two runs in seven innings on a pair or solo homers by Robinson Cano.

Now the Yanks have had difficulty with lefties this season and have not faced Jon Lester. And it is possible that right now Clay Buchholz is Boston’s second best starter. But since throwing his no-hitter on Sept. 1, he had appeared in relief just one time as the Red Sox’s version of the Joba Rules limit his innings.

Wang, who used to have such trouble against the Red Sox, has held them to two runs over 131/3 innings in his last two starts, and Pettitte has three quality starts this year against Boston. But the mystery for the Yanks down the stretch is who else will emerge to round out the rotation? Will Clemens be healthy enough and Mussina effective enough? Will Phil Hughes or Ian Kennedy prove precocious enough to trust in October?

“I don’t want to handle ‘us vs. them,’ ” GM Brian Cashman said of his Yankee rotation vs. the Red Sox. “But we are very comfortable with our first two starters, and after that we have both a lot of potential and a lot of questions. Past our front two guys you have every end of the spectrum possible.”

joel.sherman@nypost.com