The Great Home Run Derby of the 1998 baseball season has been a savior for baseball, and a scheduling and logistical nightmare for the game's network and cable rights holders. Both Fox and ESPN are now scrambling, almost by the minute, to be in proper position for the day, or night, when Mark McGwire and/or Sammy Sosa ties or breaks Roger Maris's record of 61 in a single season.

If one or both players are at 60 homers -- McGwire is now at 59, Sosa at 56 -- they will get plenty of national television exposure, starting on Saturday when Fox has McGwire's Cardinals playing Cincinnati at 1 p.m. in St. Louis as one of its regional games, with every McGwire at-bat shown live.

Major League Baseball and Fox and ESPN also announced this week a series of decisions that will ensure more coverage than originally expected. And sources said yesterday that NBC Sports, which has a piece of baseball's postseason package, may also get involved in airing McGwire and Sosa games if they are still meaningful in the home run chase and there are national scheduling conflicts -- especially on Sundays with the NFL -- with other baseball rights holders.

"It's still a work in progress," said Major League Baseball spokesman Rich Levin. "You want to get as much national exposure as you can, but in some cases, the networks involved are committed to other programming. They've got to make a lot of decisions."

This much is known, sort of. ESPN will show the Cubs-Cardinals game Monday (Labor Day) at 1 p.m. FX, the cable arm of Fox that reaches 37 million viewers, will carry Cubs-Cardinals on Tuesday, but that game will be switched to the main Fox network if either player has 60.

ESPN will air the Cardinals-Cincinnati Reds game on Wednesday. Fox Sports Net, carried locally on HTS, will broadcast split national coverage of the Cardinals-Reds and Pirates-Cubs games on Thursday, Sept. 10. Viewers will see one of the games, and the at-bats of McGwire or Sosa in the other, and one of those games still could move to Fox if 60 or 61 is imminent.

If one or both players are at 60, Fox will carry the Cardinals-Houston Astros night games on Sept. 11 and 13. Even if neither man is at 60, Fox has already added the Cardinals-Astros game on Saturday, Sept. 12, to its regional coverage, as well as the Milwaukee Brewers at the Cubs.

And Fox is still negotiating with Major League Baseball about Cubs games Sept. 11 and 13, which are scheduled to be seen on WGN, the Chicago superstation that is available on a number of cable systems around the country. Fox would like to supplement WGN coverage by putting the games on its regional cable network, adding to the national audience.

"As they say in sports, we're day-to-day," Ed Goren, Fox's executive producer, said yesterday. "Major League Baseball has somebody assigned to doing projections on these guys, and every day, the projections change. I'm not going to sleep until it's over. I'm caught up in the excitement of it as a fan, but on the professional side, it's like a general trying to move his troops to be at the right place and the right time in a battle. It's a heck of a puzzle."

There also is a minor skirmish involved, as well. ESPN petitioned Major League Baseball to air Tuesday night's game between the Cardinals and Cubs, and has told baseball officials it is willing to take any game between the two teams it can possibly get outside its Wednesday and Sunday night windows.

Instead, MLB gave next Tuesday's game to FX, with about half the number of viewers as ESPN's 75 million. Though no one will say so publicly, several ESPN sources indicated they believe this may be a reprisal by baseball against ESPN. The cable network tried to move three September Sunday night baseball TV games to ESPN2 after it was awarded the NFL cable contract last January.

But Major League Baseball refused to allow the move to ESPN2, saying the games would only be broadcast locally. Baseball officials say they made the decision to give FX the Tuesday game only because they had moved the Sept. 12 Cardinals-Astros game from FX to Fox, and owed FX another game according to its contract.

"I guess ESPN is looking at it as a payback," said Levin. "It's not. We had an obligation to Fox. We've had a good relationship with ESPN. This is not retaliation."

According to Goren of Fox, the network's sports division has been getting extraordinary cooperation from its entertainment division to remain flexible on the McGwire/Sosa front during prime time.

"It's really unprecedented, especially at this time of year while we're premiering the fall schedule," he said. "We've spent millions promoting these shows, and on September 11, we're pre-empting four new sitcoms for baseball if we have to. They've provided us the opportunities to do this thing right.

"I can't tell you how many times a day we're in touch with Major League Baseball, with our prime time people, with our sales people, with our people in the trucks trying to figure out where they're going next. "You know what it's like? The NBA lottery. Starting on September 8, right now we have five ping-pong balls in the bin that can be picked between the network, FX and Fox Sports Net. That's a good position to be in. But the way this is going, who knows?" McGwire, Sosa on TV The TV schedule for the next week for games involving Mark McGwire of the St. Louis Cardinals and Sammy Sosa of the Chicago Cubs: Day

McGwire/TV

Sosa/TV Today

No game

No game Friday Cincinnati 8:10 p.m./None

at Pittsburgh 7:05 p.m./WGN Saturday Cincinnati 1 p.m./WTTG-5

at Pittsburgh 7:05 p.m./WGN Sunday Cincinnati 2:10 p.m./None* at Pittsburgh 1:35

p.m./None Monday Cubs 2:10 p.m./ESPN, WGN

at St. Louis 2:10p.m./ESPN,

WGN Tuesday Cubs 8:10 p.m./FX, WGN

at St. Louis 8:10 p.m./FX,

WGN Wednesday at Cincinnati 7:05 p.m./None Pittsburgh 2:20 p.m./None Sept. 10 at Cincinnati 7:05 p.m./None Pittsburgh 8:05 p.m./HTS,

WGN * If McGwire has 60 home runs before Sunday, Fox may pick up game; starting time may be 4:10 p.m.