CHICAGO -- It is true that the Chicago Cubs, through their first 53 games, led the Major Leagues in both runs scored and on-base percentage, making them an elite offense, at least for one-third of a season.

And it is true that the dominant Cubs topic of any given day is left fielder Alfonso Soriano; plus or minus, hero or villain, godsend or disaster, depending on whether he has just hit a home run or botched a fly ball.

But on the issue of whether these Cubs could become, well, let's just say it -- championship Cubs -- these topics, as compelling as they might be, are not the core questions. The core question for any club with championship aspirations inevitably turns out to be: Is the pitching, in particular the starting pitching, good enough?

That kind of question often takes the full 162 games to be completely answered, and then portions of October, for those fortunate enough to last that long. But this much can be safely said this early: The Cubs' starting pitching is significantly better than many expected it to be. Combine that with an effective offense, and the possibilities are legitimately lofty.

At the close of business on Wednesday night, the Cubs had a 3.56 team ERA, and it did not look like a statistical aberration.

The Cubs just swept the Dodgers in a three-game series, because they limited Los Angeles to three runs, one run in each game, no more, no less. The Cubs themselves scored only eight runs in the three games, so this was a pitching-first sort of sweep. These felt like classic, low-scoring postseason contests, although the weather for the last two games was more November than October.

The Cubs won the Wednesday night finale, 2-1, in the 10th on a game-winning single by, all right, Soriano. But they were placed in a position to win by eight gritty innings of work from Carlos Zambrano.

Zambrano had momentary control lapses and required by far his highest pitch count of the season -- 130 -- to work those eight innings. But he never let a problem become a crisis, and he gave up only one run.

He is pitching like the ace of a staff should. He has given up two or fewer runs in eight of his 12 starts. He has not lost a decision since April 11. He is 7-1 with a 2.33 ERA.

The rest of the rotation news has been, if not uniformly tremendous, good enough to give the Cubs the best record in the National League with nearly two months in the books.

Lefty Ted Lilly, if he started slowly this season, has rounded into better form, did win 15 games last year, and is a terrific competitor.

Beyond that, there was a substantial question about what would happen with Ryan Dempster's conversion from closer to starter. This is what happened: In 11 starts, Dempster is 6-2 with a 2.56 ERA.

This should not be completely shocking. Dempster had 162 big league starts before he found steady bullpen work. This is not unknown territory for him. It is just that he is a better starter than he was earlier in his career. It is too early to gloat about Dempster's successful return to starter status, but it is not too early for the Cubs to be encouraged.

The most recent, and perhaps most encouraging, development has been the work of Sean Gallagher, a 22-year-old with a mid-90s fastball and uncommon composure. In a 3-1 victory over the Dodgers on Tuesday night, Gallagher gave up just one run on four hits in seven innings. This kind of a dominant performance by someone not in the original rotation plans, by someone making his fourth big league start, can energize everybody involved.

"What helps give a lot of good vibe for the team is Sean Gallagher having a great outing like he did," catcher Geovany Soto said. "This guy just came here, and look how great he's doing. Everybody's pumped up. The veterans see that."

The manager, Lou Piniella, sees it, too.

"Gallagher is pitching well," Piniella said. "And he's learning as he's going. That's one good thing about young kids -- they can learn on the go, and they can get better on the go. If you've got good stuff and you apply yourself, inexperience is no detriment, believe me. It can almost be a positive. I like kids with good arms, and I like kids that apply themselves and have confidence in themselves and go out there and let it loose."

To the question of whether Gallagher had pitched himself into the rotation for a considerable length of time, Piniella smiled slightly and replied:

"You all want to know, I'll give you the rotation through Sept. 3. I'll let you know who's pitching on Labor Day in about three minutes. Look, he's pitching well. Why tinker with something that's working? Let the kid pitch."

That seems like a reasonable approach. The only starter who has not offered the Cubs consistent encouragement is Jason Marquis (2-3, 4.97 ERA). But it is not as though he has been hopelessly outmatched, either. He has won 70 games in his career, including 15 in a single season. His performance has not risen to the level of his stuff during portions of his career, but this is not a case of sending somebody without hope to the mound on a regular basis.

This is not a rotation loaded with certain Hall of Famers, but nobody else in the contemporary game has one of those, either. With a good offensive club, what the Cubs will need is a rotation that varies in quality only somewhere between reliable and, when necessary, very good.

The good news from the Dodgers series was that very good was required from the Cubs starters three times, and three times in a row they were up to the task. That is the kind of solid pitching that will pay off well beyond late May.