WASHINGTON - You buy a sleek, new sports car. But you don't do the scheduled maintenance. You leave the windows down when it rains. You run over potholes. Even though the engineering is great, you're not going to get the most out of your money.

Or you purchase a racehorse with great bloodlines. But you hire a trainer without much experience. You don't insist that it gets the best feed and grooming. No matter how talented, that horse isn't going to win the Kentucky Derby.

Top starting pitchers are sort of the same way. They might have the kind of stuff that has batters muttering unprintables to themselves as they trudge, head down, back to the dugout. They might shatter bats and big-league dreams with equal ease. Most of the time, however, they can't do it all by themselves.

Roy Oswalt made his Phillies debut last night, capping a whirlwind 48 hours during which the Astros agreed to trade one of their cornerstones, financial concessions were hammered out, Oswalt agreed to waive his no-trade protection, flew from Houston to Washington to join his new team and then - whew! - started last night against the last-place Nationals.

His outing was less than spectacular. He gave up five runs (four earned) in six innings of an 8-1 loss. That's not a big deal. He should get 11 or 12 more starts before the season ends. The sum of those will weigh more heavily in the final evaluation of the deal than last night.

(That Oswalt has now given up 12 earned runs on 23 hits in 15 innings over his last three starts is a little bothersome, but shouldn't be an issue as long as he's healthy and the Phillies are convinced he is. That J.A. Happ, who went to Houston, gave up just two hits in six shutout innings in his Astros debut last night should not be overblown, either. Think of it as the baseball gods having some wicked fun.)

What was notable is that, as they have so often this year, the Phillies came up small for one of their building-block starting pitchers.

They have scored three or fewer runs 14 times when Roy Halladay has started this season, including two or fewer eight times.

They've scored three or fewer 10 times when Cole Hamels starts, including two or fewer eight times.

Not only did they score just once for Oswalt last night, they also made a couple of errors behind him. One was a bizarre play on which catcher Carlos Ruiz fielded what was supposed to be a sacrifice bunt by Adam Kennedy with runners on first and second. Ruiz then fired a strike to third . . . except that nobody was covering. Third baseman Greg Dobbs took the heat, saying he misread the ball and should have gotten back to cover; it led to an unearned run.

"[Oswalt's] stuff was good," manager Charlie Manuel said soothingly. "He had a little trouble with his command, but I like his stuff. He's going to be fine. We played a little sloppy behind him."

For some reason, too, he's had his problems with the Nationals. Over the last two seasons, he's 0-2, 7.45 in four starts against Washington.

It just so happened, in one of those delicious coincidences that make baseball so interesting, that Oswalt checked into the same visitors' clubhouse yesterday that had been vacated the day before by the Atlanta Braves.

And it was while the first-place Braves were quartered there Thursday that they heard about the deal that had the potential to alter the balance of the power in the National League East between them and the fast-closing Phillies.

With the gap between the two clubs as narrow as it's been in almost a month, the Atlanta players reacted to the fact that Oswalt was coming both figuratively to their division rivals and literally to the space they were currently occupying.

"They have Roy Oswalt. So what? They've got Roy Halladay," catcher David Ross told the Atlanta Journal Constitution. "If you're thinking you've got a chance to win a world championship, which we feel that we have a good enough team to do, then you're going to have to beat good pitchers period, the best."

Righthander Derek Lowe said the Braves were prepared for the move because of all the speculation that had preceded it. "It was just a matter of who they were going to give up," he said with a shrug. "[But] it's definitely going to help their team, no doubt about it."

A lot has been made of the mental boost getting a top player at the deadline can make as well as the letdown that can occur for clubs that don't.

The Phillies got Oswalt. The Braves got shortstop Alex Gonzalez and, with just hours to go before the gong strikes, had come up short in their quest to add an outfielder.

In the battle of the trading deadline, the Phillies have already won.

In the battle to make it back to the World Series, though, the Phillies need to do a better job of supporting their best starting pitchers.

Send e-mail to hagenp@phillynews.com