The National League Central has become baseball's version of The Improv.

Since the All-Star break, the Cardinals, Reds and Astros have started members of their Opening Day rotations in only 43 of a combined 88 games. It's fair to say the team that winds up winning this division will be the one that does the best job improvising.

	Roy Oswalt is 4-1 with a 2.59 ERA in six starts since the All-Star break.

While St. Louis and Cincinnati have imported starters who are known quantities, Houston has had to find its help within its own farm system. Yet it is the Astros, after losing Shane Reynolds and Carlos Hernandez, who have done the best job of changing on the fly.

It remains to be seen if rookie Kirk Saarloos and journeyman Peter Munro can keep this up with each start bringing a little more late-season heat. But they've filled in admirably behind Roy Oswalt, Wade Miller and Dave Mlicki, helping Jimy Williams' team go 19-11 since the break.

With Saarloos and Munro combining for a 7-2 record and 2.79 ERA in 10 second-half starts, Houston has climbed within three games of St. Louis (and five of Los Angeles in the wild-card race) entering this week. The Astros' 3.50 ERA in the second half is significantly better than both St. Louis (4.38) and Cincinnati (4.70).

Oswalt and the guys at the end of Houston's bullpen have gotten on rolls. Oswalt heads into a Monday night start at Wrigley Field having allowed one earned run in 22 2/3 innings over his last three starts.

After Oswalt's last start, Florida's Kevin Millar paid him the ultimate compliment, comparing him to Pedro Martinez. "He has that electrifying explosion,'' Millar said. "He has a jerky delivery, and he comes at you with the same arm angle on both of his pitches. He's the real deal. He comes at you with a 96-mph fastball and then takes off 22-mph on his breaking ball.'' Pedro Borbon, who was acquired by the Astros from Toronto in mid-May, has joined Billy Wagner and Octavio Dotel to give Houston a reliable -- and often electrifying -- trio of arms at the end of the bullpen. They have 52 strikeouts between them in 44 1/3 second-half innings. Dotel has allowed only nine hits in 19 innings.

General manager Gerry Hunsicker hasn't ruled out making a deal or two before the Aug. 31 deadline for playoff eligibility. He's continuing to monitor the players who slide through waivers and says "there's no way to know what will happen in the next month.''

You don't have to tell Cardinals manager Tony La Russa or GM Walt Jocketty about the unpredictable nature of life, let alone baseball. The Cardinals continue running in place as they try to make this numbing season a tribute to the legacy of the late Darryl Kile.

La Russa has used seven starters in the second half, with only 11 of 29 games started by guys who were there at the start of the season. Matt Morris is the only Cardinals starter who has gone the distance.

Jason Simontacchi, the former Italian Olympian from California, was a lifesaver earlier in the season but is showing wear (0-3, 7.45 in six starts) since the All-Star break. Chuck Finley, who threw seven shutout innings against the Mets on Sunday, may finally be hitting his stride after the July trade that brought him to St. Louis from Cleveland. He's an underwhelming 3-2 with a 4.71 ERA in five second-half starts.

Andy Benes, who appeared headed to retirement earlier in the season because of arthritic knees, rejoined the rotation when Woody Williams joined Garrett Stephenson on the disabled list.

"Well, when I took economics in high school, economics was supply and demand, right?'' said Benes, who has gone 1-1 with a 2.08 ERA in 30 1/3 second-half innings. "The (pitching) supply was low and the demand high. So here I am.''

Williams, out since July 7 with a pulled muscle in his side, has begun throwing off the mound, but probably won't be back until late August, if then. Stephenson, who has twice been on the disabled list with back and hamstring issues, appeared close to returning before having to be scratched from a rehab start on Aug. 10 with pain in his shoulder.

Given the pitching shortage, Jocketty might ultimately regret sending Mike Timlin and Bud Smith to Philadelphia in the Scott Rolen trade. Timlin earned victories in three of his first seven appearances for the Phillies.

Speaking of Rolen, he hasn't exactly provided the offensive lift that was predicted. Even with nine runs on Sunday, the Cardinals have averaged only 2.9 runs in their last 10 games, scoring one run or less in six of those games.

Low-scoring games put the focus on pitching.

Cincinnati, which broke out to a 25-15 start, is frantically trying to hang in the Central race with an overhauled rotation. Elmer Dessens' recent trip to the disabled list leaves Jimmy Haynes as the only constant in a group that has been kept afloat by newcomers Brian Moehler and Ryan Dempster.

Joey Hamilton, winless since May, and knuckleballer Jared Fernandez fill out a rotation that hardly seems likely to get a team into the postseason. No wonder GM Jim Bowden says "sometimes heart means more than talent.''

Had owner Carl Lindner given him the go-ahead to spend money, Bowden believes he could have worked out trades for Bartolo Colon, Jeff Weaver and Finley (not to mention Cliff Floyd and Rolen). But the Reds haven't had that kind of money to spend in decades.

So pitching coach Don Gullett will have to continue to make the best of a tough situation. That's a familiar feeling in this division.

Spotlight: Sammy Sosa
Some star players hold themselves accountable for their teams' performances. Most self-centered ones try to distance themselves when things go bad.

	Sammy Sosa Right field Chicago Cubs Profile
	2002 SEASON STATISTICS GM HR RBI R SB AVG 112 39 89 95 2 .308

You don't need a decoder ring to know which camp Sosa belongs in.

After chiding management for not surrounding him with more talent, Sosa said he might just walk away as a free agent after 2003 by failing to exercise a mutual option for the last two years of the four-year extension he signed in March, 2001. He says he's tired of having his big years wasted.

Of course, this is the same Sosa who lobbied hard for the addition of Moises Alou, proclaimed this as a great team in spring training and then failed to come through time and time again in April and May, when a 13-27 start robbed the rest of the season of its essential meaningfulness.

Well, meaningless for most, but not Sosa. In vintage form, he is killing the ball now that it matters only to rotisserie heads. His four-homer, 14-RBI onslaught on Saturday and Sunday at Coors Field was so Sammy.

Sosa is leading the league in homers (39) and runs (95) and has moved near Lance Berkman's lead in RBI (89). He's even got his average with runners in scoring position up to .293 (it was barely over .200 two months ago). His team is in fifth place, but don't blame that on him.

New face: Devil Rays LF Carl Crawford
Having turned 21 just a week ago, Crawford is establishing himself as a player to watch. He's hitting .300 with one homer and 13 RBI in 23 games since being promoted from Triple-A Durham on July 20.

Crawford hit his first major-league homer Saturday at Kansas City. It was part of a series in which he was 4-for-13 with every variety of hits.

Manager Hal McRae has made Crawford a fixture in left field. His long-term status there is at least as certain as the team's.

When the Devil Rays promoted Crawford, GM Chuck LaMar said he probably wasn't ready for the major leagues. "But the combination of his mental toughness, the experience that will continue to help his development and the situation we're in all led to his call-up,'' La Mar said.

Talent also doesn't hurt.

Team to watch: Oakland Athletics
The best team in the AL West the last two months, Oakland is hot again. After winning eight of their last 11, the A's are 40-20 since June 6.

During that stretch, they have gained five games on Seattle and 5½ on Anaheim. If you do the math, you see the seven weeks remaining is more than enough to make up the rest of the deficit.

Art Howe's team is coming off an ultra-impressive 4-2 road trip to Boston and New York, which could have been even better. The A's won the first two games in both series but were denied sweeps with Barry Zito facing the Red Sox and Mark Mulder going against the Yankees.

It's a must for Oakland to continue playing well on the road. It returns to the Coliseum for a six-game homestand against Toronto and the White Sox, beginning Monday, but after that will play 17 of 22 on the road. That includes series at Cleveland, Detroit, Kansas City, Minnesota and Anaheim.

More and more it looks like the West will be decided in the final three weeks of the season. During that stretch, the A's play six games against Seattle and eight against Anaheim. The Mariners play 12 of their last 16 games against Anaheim and Oakland.

Phil Rogers is the national baseball writer for the Chicago Tribune, which has a web site at www.chicagosports.com.