And this year, it's the two teams with the best records in the National League. When looked at in that light, the NL Central Division is not quite big enough for both of them.
This rivalry needs no introduction, being more than 2,200 games old. The intensity is not contrived. The fan bases of the two clubs intersect, overlap, intertwine, all of that and more, in the prairies of Illinois, where there is room for that sort of thing. This is the foremost baseball rivalry of the Midwest, and it does not have to settle for nice-try-but-second status.
"It's a nice rivalry, it really is," Cubs manager Lou Piniella said. "You know, I was there with the Yankee/Boston stuff. This one parallels that one."
The Cubs and the Cards will settle for that designation. For purposes of national media attention, the Red Sox and the Yankees sometimes seem to be the only two rivals that matter. This is an unfortunate and inaccurate reading of the situation, but this traditional Middle American argument on either side of the Mississippi has its own merit, no matter who recognizes it.
This three-game series has obvious importance, with the Cardinals just 2 1/2 games back of the Cubs when coming in. But these meetings don't require the one-two positions in the standings for them to work.
"I like being in contention this time of the season," Cardinals manager Tony La Russa said. "But I don't care what position you're in, when you play the Cubs, it's always exciting. They have their own different kind of excitement."
The Cubs still lead the overall series, which seems a bit strange, since from the standpoint of World Series championships, the Cardinals seem to have had an edge over the Cubs for, oh, roughly the last eight decades. But this year, at least the first half of this year, appears to be different. Even though the Redbirds have vastly exceeded everybody's expectations but their own, 2008 has had the look of being a Cubs season.
While Piniella cautioned against placing an inordinate amount of importance on this series, saying, "regardless of what happens, nobody is going to win or lose this division this weekend," Friday night was a bit of a landmark evening for the Cubs.
Carlos Zambrano returned from the disabled list, and not a moment too soon. "We need to get him out there pitching again," Piniella said. "Since he's been on the DL, we haven't pitched nearly as well. I don't know if it's a coincidence, or something that was going to happen anyway. We have struggled, pitching-wise. I think we've gone from first to fourth in team ERA, in a short period of time. I'm hoping he'll come in and stabilize things."
Stability was achieved for this Friday night, Zambrano working six shutout innings, his right shoulder, previously tender, but now seemingly in tip-top shape, his stuff not suffering from any rust. Only the duration of this start differed from his best work, the Cubs choosing to limit him to 90 pitches. Zambrano did his bit, working with efficiency as well as effectiveness, needing only 87 pitches to get through six innings.
The result was a 2-1 Chicago victory, assuring the Cubs that they would depart St. Louis as a first-place club.
The hidden benefit from losing Zambrano's services for two weeks could be that he may be fresher later in the season.
"It may affect your numbers," Zambrano said of missing some time, "but that doesn't matter when you think of helping your team, not only right now, but at the end of the season and in the playoffs."
The Cardinals fans had their moment in the eighth inning, when Albert Pujols belted the 300th home run of his career. Pujols became the fifth youngest player (at 28 years, 170 days) to reach 300 homers. Two more days and he would have been older reaching 300 than the previous fifth youngest, Mel Ott.
The Busch Stadium crowd was, of course, a capacity house, 46,450 on hand. This was not the usual sea of red, because it was dotted with Cubs blue. When closer Kerry Wood recorded the game's last out on a grounder to second, the cheer that went up was far from insubstantial.
It was a splendid night for baseball, and our nation's 232nd birthday; 75 degrees at game time, with a bit of a breeze. The local fireworks display at the riverfront started in the top of the ninth, both clearly visible and completely audible beyond right field. It was an impressive fireworks display -- you had to like the giant orange bursts, particularly -- although the timing drew a few mild questions.
"I've never seen that in the bottom half of the ninth inning," Piniella said. "It had to be a little distracting to the players out there."
Cubs catcher Geovany Soto, whose fourth-inning home run turned out to be the margin of victory, chuckled when he was asked about the fireworks, but said of catching the bottom of the ninth in the face of a full-fledged Fourth of July celebration:
"Once you put the sign down, you just block out everything. You hear stuff, but you don't. You just focus on the game."
The birthday of the American Republic must be celebrated with suitable festivity, and the occasional massive fireworks display colliding with the ninth inning of a tight, important game does not seem like too large of a price to pay. Anyway, for some of us, the Cubs and the Cardinals playing baseball is truly a celebration of The Fourth and of America itself.
Mike Bauman is a national columnist for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.