The Nationals fans come, they cheer, and they bounce up and down in the RFK Stadium stands like human Jell-O. Perhaps after 33 seasons without major league baseball they even rejoice. But do the crowds, like the near-capacity throng expected on the Fourth of July, understand yet what it is that they are watching? Do we have any idea how remarkable a sight we're seeing?

If the Nationals wore jerseys with the name of a different city on the front, one that had not been exiled from baseball for a third of a century, would the meaning of a 50-31 record at the midpoint of the season have a fuller and more dramatic weight? When the Boston Red Sox finally managed to "Reverse the Curse," the whole nation understood its meaning both as a baseball event and as a social phenomenon played out over many generations.

But the Nationals' story, now only at its halfway point and in danger of being derailed at any time by a prolonged slump, is far harder to grasp because everything has happened in the last 36 days. On May 28, the Nats were an appealing team, quickly collecting a local following, but a club with a losing record (24-25), more injuries than any team in baseball and, it appeared, a full-time job on its hands simply to remain respectable. Now, what on earth are we to make of the team before us?

Leave aside the indigestibility of the Nationals' six-game lead in the National League East or its 100-win pace after losing 95 games last season in Montreal. Take a smaller focus. Do those who root for the Nats even grasp what Washington did in Sunday's game against the Cubs to complete a sweep in Chicago?

The Nationals ignored a blown 2-0 lead in the ninth by young Chad Cordero, then shook off a 4-2 blown lead in the 11th by old Hector Carrasco and Joey Eischen before finally winning, 5-4, in the 12th inning on a home run by Brian Schneider, who circled the bases stoically in his whaler's beard.

Nothing, viewed psychologically or statistically, has as debilitating an effect on a team as one blown save, especially when a team is just one strike away from victory. Such a squandered lead often cascades immediately into a losing streak.

To blow three such last-strike opportunities -- baseball match points -- ought to be devastating. Especially when the other team's comebacks are built, as the Cubs were, on a two-out, two-strike flare hit in the ninth, then a two-out, two-strike dribbler by the same hitter (Jeromy Burnitz) in the 11th inning. Finally, Chicago tied the score at 4 when Todd Hollandsworth shattered his bat and dumped a lucky bloop hit into right field on a pitch that was ankle-high. Surely, the Nats' magic in one-run games was finally kaput.

Yet the Nationals, playing without their regular first baseman, second baseman, shortstop and left fielder, won with what amounted to their junior varsity. As Schneider rounded the bases on his two-out homer, leaving the Cubs dumbstruck in their dugout, he showed almost no emotion. Too tired? Or simply reflecting the fierce understated resolve of this team? When Carlos Baerga caught the last throw at first base, he simply threw his arms up in the air.

When the $205 million Yankees or the $121 million Red Sox are hurt, they can still overpower opponents (in theory) with waves of proven talent. But the Nationals, with a $48 million payroll, have had to conduct a scavenger hunt to amass, in their manager's words, a collection of "outcasts" and "misfits." By all conventional baseball logic and analysis, such a humble assemblage should have crumbled long ago. At the least, they should not be on a 26-6 tear, playing better as they subtract stars.

Instead, since a pivotal day in St. Louis when Livan Hernandez beat the defending National League champion Cardinals, 3-2, the team has won and won and won, always by one or two runs, it seems, and as a result not so much of talent but by craft or providence or stubbornness or perhaps an oblivious pleasure that accompanies their escape from Montreal.

Finally, as the team has risen to the third-best record in all of baseball, the whole daily process of discovering how the Nats have won again has become downright silly. Did Cordero load the bases with nobody out in the ninth inning and a one-run lead before getting a popup, a strikeout and a popup? Did Manager Frank Robinson, soon to be 70 and with an artificial hip, try to brawl with Angels Manager Mike Scioscia? Or did Frank merely get the umpires to turn a fair home run against the Nats into a foul ball? Perhaps the natural culmination to such a first half was the Wrigley Affair as the Nats swept a team that may, eventually, be one of its primary competitors for the NL wild-card spot.

Just as grief has its stages, perhaps unexpected jubilation does, too. We'll have to see how this progresses. Little work has been done in the field of Joy Research. Right now, we've gone from surprised April vindication to a period of self-protective May skepticism to a blitz of June and July victories that stuns even the Nationals.

So, what are we watching on Independence Day in RFK when the Nats come home? Like mentioning a no-hitter in the fifth inning, you don't want to use foolish words prematurely. Baseball often swamps its most cheerful story lines with swift, unsentimental and capricious events that can engulf even the best-constructed teams. If ocean liners like the Yankees can run aground, what do we make of a lashed-together raft like the Nationals?

So you bite your tongue with October talk. But you can't prevent yourself from thinking. And this is what you think: For half a season the Nationals have played baseball exactly as it is supposed to be played. Because they have nothing to lose and respect to gain, they play to win, not to avoid defeat. Because little is expected of them, they band together for mutual security.

"We keep saying, 'We have each other's backs,' " pitcher John Patterson said.

As their various injured regulars return, what will the effect be? The first such fellow, southpaw Eischen, came back in Chicago. And what did he do? Eischen came out of the bullpen in extra innings to get the win in the final game at Wrigley.

Many around baseball still say that the Nats are merely a .500 team playing on inspiration. To illustrate that disrespect, NL all-star manager Tony La Russa, whose defending league champion Cardinals have a 51-30 record that is just one game better than the Nats, had the gall on Sunday night to leave both Jose Guillen (17 homers) and Nick Johnson (.320, though headed to the disabled list), both hard-nosed Nats leaders, off the squad.

In baseball, the numbers seldom lie. If the Nationals, with .300 hitters like Jose Vidro, Ryan Church and Johnson returning to their lineup soon, can play 40-41 ball in the second half, Washington will end with 90 wins. That often suffices to extend a season. Anything more will surely keep them in the October hunt deep into September.

Who knows, perhaps the Nationals will even have a chance to demonstrate to La Russa, on some crisp autumn day, that he should have invited more of them to that all-star party in Detroit.

Whether it makes sense or not, all-star reliever Chad Cordero and the Washington Nationals continue to line up victories -- 50 of them so far.