During their eight-game winning streak, the Yankees have outscored their opponents by a stunning 65-30 margin. They’ve batted .308 AVG/.369 OBA/.589 SLG, which is to say that the offense as a whole has turned into a 14-man embodiment of Vlad Guerrero.

Tino Martinez alone has batted .333/.378/.974 in May, clubbing eight of the team’s 21 home runs during the month. The pitching staff, which couldn’t get anyone out in the early going, has posted a 2.88 earned-run average during that span, which bests the team ERA for the league-leading Chicago White Sox by nearly half a run. No matter what they did before, no matter what they do after, for the last eight days the Yankees have been the most dominant team in baseball, and Martinez has been their Lou Gehrig.

At the same time, the winning streak has come at the expense of just two teams, the Oakland A’s (14-23) and the Seattle Mariners (15-22).The A’s are in a rebuilding mode, with a young rotation and a weak offense that is further handicapped by the season-long slumps of Jason Kendall and Eric Chavez. The Mariners, meanwhile, have one foot in rebuilding and one foot in the grave. Seattle is 10th in the American League in runs scored, while Oakland comes in dead last. The two teams rank ninth and 10th, respectively, in the AL in ERA.

That said, the Yankees are doing what winning teams need to do: picking on the league’s weaker teams. Generally speaking, all pennant-winning teams need to do is split with the good teams, win a few more than they lose against the average teams, and decimate the poor ones.

The Joe Torre Yankees have ridden this model to 10 straight postseason appearances, which is what made their losses to the Tampa Bay Devil Rays so worrisome. The eight-game winning streak is a step in the right direction, but what remains to be seen is if the team can continue this kind of dominance over the small fish and extend it to the big fish when they return to intradivisional competition and face the Orioles, Red Sox, and Blue Jays, all three of which remain ahead of the Bombers in the standings.

This seems unlikely – the Yanks are, after all, an aging team playing .500 ball. But it is possible to believe that the streak signifies a 180-degree turnaround, so long as you believe that the Yankees can continue to do a number of unlikely things.

First, you believe that Tino Martinez will continue his trip to the batting cage of youth, hitting like a Bambino on Bovine Growth Hormone despite his never having slugged higher than .577 in a single season – and that in 1997, a baseball lifetime ago. Second, you subscribe to the belief that Derek Jeter, currently hitting .327/.425/.460, will chalk up his best year since 2000.

Third, you believe that Mike Mussina is back for good, that Kevin Brown can continue his chain of good starts, and that the starting pitching will be so strong overall that the weakness of the bullpen can be overlooked.

Fourth, you believe that the team can live with the weakest defense in the majors, last in both leagues in converting balls in play into outs (even during the streak, the pitching staff allowed 3.75 runs a game because the leaky gloves, particularly Alex Rodriguez, helped to cue up seven unearned runs).

Finally, you are reasonably certain that rookie second baseman Robinson Cano can hit .325 with no walks, and that the offense can thrive despite a light-hitting infielder in left field and an enervated designated hitter – and that even if some of these things do not come to pass, Jorge Posada and Hideki Matsui will remember how to hit and carry the team for a while.

If you do believe these things, you have religion, and you may very well be right; the Yankees have rewarded their faithful innumerable times. But the day of reckoning is approaching.

There are nine games left until the Yankees next face Boston: three against the Mariners, then three each against the Mets and the Tigers, two teams with more pluck and talent than either the A’s or the M’s have displayed. They will be the first test of the Yankees’ May renaissance. Boston’s will be the second, and last.

For now, at least, the Yankees’ glass is half full. In mere days, we will know if it was full of promise, or full of illusions.