Despite Sunday night’s multi-grand slam fireworks from Cliff Floyd and Carlos Beltran, it might be time to reassess which of New York’s baseball teams is the best. Sure, the Mets have run away with their division, but that’s as much an expression of the failings of the competition as it is of their own dominance.

To say that the Mets are the club in the division, and possibly the league, that was actually able to put together something resembling a fully rounded team is no insult to their planning or their execution, but it doesn’t mean they’re actually a great team. They’re great only in context. Removed from that context, as they were in interleague play — during which they went 6–9, and as they will be if they go to the World Series — they may prove to be quite mortal.

While the Mets were taking two of three from the Chicago Cubs, the Yankees were in the process of sweeping the Cubbies’ crosstown cousins, who happen to be the defending world champions. The sweep, unexpected in a season in which the Yankees have played quite well overall but have had a hard time maintaining their momentum, boosted the junior circuit’s New York entry into a virtual tie with the Mets. The Yankees’ winning percentage is .596; the Mets’ is .598. At this writing, the Yankees have played 89 games and the Mets 92; the Mets went 2–1 in the three games the Yankees haven’t yet played. That’s the only difference between the two.

Given team health, the Yankees are strapped for talent as compared to the Mets. Sunday’s starting outfield at Yankee Stadium consisted of Melky Cabrera, Bubba Crosby, and Aaron Guiel. This is a far cry from Keller, DiMaggio, and Henrich. While the left side of the infield boasted Hall of Fame-bound Alex Rodriguez and Derek Jeter, the right side held Miguel Cairo and Any Phillips, neither of whom can boast even a .300 on-base average. The Mets have no comparable players in their starting nine. Even Cliff Floyd has escaped from his early-season doldrums thanks to a scorching .371 AVG/.488 OBA/.714 SLG in July.

The Yankees may actually have more depth than the Mets in the pitching department, at least right now. It seems unlikely that a team that will be devoting tonight’s game to excavating the pitcher trapped inside the bloated remains of Sidney Ponson’s career could ever be called “deep.” But with Pedro Martinez on the disabled list, Tom Glavine compiling an ERA of near 5.00 in his most recent starts, Orlando Hernandez being more variable than the wind (in his last two starts El Duque has shut out the Pirates for seven innings and been bombed by the Cubs), Steve Trachsel posting a 0.67 strikeout-walk ratio over the last six weeks, and fifth starters coming and going like a daily soup special, the Mets could coast through the remainder of the regular season only to find themselves disarmed in the playoffs.

In their book “Baseball Between the Numbers,”the team at Baseball Prospectus showed that three factors that correlate strongly to postseason success are having a strong defense, a strong closer, and a high strikeout rate. The Mets check out on the first two and have been above average in the third this season, but in the last 30 days they’ve been a little below average.

This can be laid at the feet of the erratic starting pitching. The reason this will be a key factor in the postseason is that bad things can happen when powerful American League offenses (or, for that matter, Albert Pujols) are allowed to put wood on the ball.

Yankees pitching hasn’t been pretty, but since mid-June it’s been about on par with that of the Mets, if not fractionally better. In that time the Mets have allowed 5.3 runs per nine innings, the Yankees 4.9. Given that Shawn Chacon’s ERA was 12.66 in his last two starts, the Yankees can only hope that Ponson pitches as badly as he did with the Cardinals, because he’d be at least 50% better.

Three starting pitchers have turned in consistently strong performances. While Randy Johnson has been up and down and the fifth starter awaits a whale the Yankees hope they have harpooned, Mike Mussina, Chien-Ming Wang, and Jaret Wright have pitched consistently well. None has been dominant, but all have held the opposition under four runs.

Returning to Baseball Prospectus’s postseason checklist, the Yankees’ defense is functional if not the rangiest in the bigs. It is, at the very least, more adept than most at turning balls in play into outs. Robinson Cano and Melky Cabrera have given the Yankees a defensive look they haven’t had during the Torre era: an adept second baseman and an outfielder with an arm.

The Yankees also pass the strong closer test with flying colors. Like the Mets, they have difficulty in the strikeout department; their rate has been only average throughout the season, though whereas the Mets have declined recently, the Yankees have improved. This is largely due to the improved performances by Johnson and Wright and continued good pitching by Mussina. It’s ironic, though, that Wang may prove to be the difference between making the playoffs and going home but that his particular brand of stuff could be a liability in October.

October play is seemingly guaranteed for the Mets but no sure thing for the Yankees. Still, as things currently rest, these two teams are very closely matched, and even if the Mets go on while the Yankees yield the division title to the Red Sox, it will prove nothing. It’s not how many battles you won, it’s who you fought to win them. This time the Yankees drew the tougher bracket.

Mr. Goldman writes the Pinstriped Bible for www.yesnetwork.com and is the author of “Forging Genius,” a biography of Casey Stengel.