When you write about the Yankees as frequently as I have for as long as I have, there are certain reader responses that tend to crop up with regularity in your inbox. It doesn’t matter what the context is. If the team is winning or losing, the reaction is the same. For example, if you say, “Left fielder Rondell Ward can’t hit. The Yankees need to upgrade before the trading deadline, perhaps by adding former MVP Barry Ordonez, who is said to be available,” you can be certain that before the day is out you will have 100 messages saying roughly the same thing: “You don’t need an all-star at every position.” But there is a difference between having a cast of name-recognition ballplayers and accumulating the level of talent you need to win.

Saying that the Yankees don’t need one more all-star is intended to be a rejoinder of such absolute authority that any argument about upgrading the Yankees lineup is automatically rendered null and void. Unfortunately the argument is basically meaningless, especially when applied to this year’s ostensibly star-heavy Yankees. What a baseball team needs is not stars but enough of a positive gap between the number of runs it scores and the number of runs it allows. The players might or might not be all-stars; they just have to be good. It doesn’t matter who the players are, but how they affect that relationship.

A team can have an offense that is dominant by most standards and yet still insufficient. Just seven teams have scored over a thousand runs in a season since 1901. Of the seven, four went to the postseason and three did not. The 1931 Yankees, who crossed the plate a record 1,067 times, finished in second place because their pitching staff allowed nearly six runs a game. You can choose to look at this one of two ways: Either the pitching staff was lousy and failed to support the offense, or the offense was inadequate to the task required of it, to overcome the weakness of the pitching staff.

This kind of formulation is unfair to the 1931 Yankees, because they really did have a team of stars — nine future Hall of Famers were on the roster, including the catcher, first baseman, second baseman, third baseman, and two outfielders, and you can’t score any more runs than they did. It works perfectly with the 2007 Yankees, who aren’t nearly so deep. The ninegame winning streak aside, the Yankees have outscored their own pitching 331–312. Over a full season, this differential would lead to a predicted record of 86 wins, not enough to get the Yankees where they want to go.

Overall, the pitching has been about average, even outside of the nine-game winning streak. The bullpen has been problematic, though not nearly as much of a suicide weapon as that of the White Sox or Orioles. The Yankees have gone 4–12 in one-run games, a devastating record. Some of those losses are attributable to the bullpen, some to Joe Torre’s strategic butterfingers, some to simple bad luck.

By contrast, the offense has been successful, though overly reliant on Alex Rodriguez, Derek Jeter, and Jorge Posada to overcome the inconsistency or outright failure of players like Bobby Abreu and Johnny Damon. Arguably, the Yankees could stand pat on hitting and try to improve the pitching staff (certainly the bullpen could be painlessly improved with options already in the system — Chris Britton and Edwar Ramirez couldn’t be any worse than the pitchers the Yankees have been using). But improving the pitching staff is a problem akin to trying to get boat traffic under a bridge by lowering the river. Pitching is in very short supply. Acquiring hitting is the path of least resistance, and would change the outlook of most Yankees games. On nights that A-Rod, Jeter, and Posada don’t hit (or in the latter’s case, don’t play) the Yankees have a hard time scoring. They need one more batter, especially a power hitter — after A-Rod, the Yankees have limited power potential.

With the Red Sox almost certainly out of reach, the wild card remains New York’s only route to the postseason. The current wild card leader, Cleveland, is on a page for 94 wins. For the Yankees to win 95 games is a near-impossibility; they’d have to win 59 of their remaining 89 games, a 107-win pace over a full season. We can pretend that the required number of wins will fall to 90. If the pitching remains at the level it established outside of the nine-game streak, the Yankees would have to score nearly six runs a game to make it.

They won’t do it with the current lineup, but could with another bat. It doesn’t matter if they get Mark Teixeira or John Smith. You don’t need a lineup of All-Stars, just a lineup that fits your competitive needs.

Whether the Yankees still have competitive needs at this point is a whole other debate.

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