The 1999 WNBA playoffs open tonight with four teams involved in single-elimination games.

After adding two teams this season, the WNBA expanded its playoff format to include a one-game playoff between the second- and third-place finisher in each conference. The second-place finisher hosts the game.

Tonight, the Charlotte Sting (15-17) plays the Shock (15-17) in Auburn Hills, Mich., and the Sacramento Monarchs (19-13) are in Inglewood, Calif., to play the Sparks (20-12).

The winning team in each conference will advance to a best-of-three series against the conference champion, the New York Liberty (18-14) in the East and the Houston Comets (26-6) in the West. The winners of the conference finals will meet in another best-of-three series to compete for the WNBA title.

"You got to win to stay alive," said Detroit Coach Nancy Lieberman-Cline, whose team, like the Sparks and Monarchs, is making its first playoff appearance. "This is what we worked for all season long. . . . There is not a whole lot of room for error."

The Shock and the Sting split four games in the regular season, with Charlotte losing its season finale at home against Detroit last Friday, 58-57. The Sting ended the season on a five-game losing streak.

"That's a tough way to end the season," Sting Coach Dan Hughes said. "I think they're hungry. They want to prove something."

The Sting is in the playoffs for the third consecutive season and has a veteran lineup led by forward Vicky Bullett (11.5 points per game) and point guard Dawn Staley (11.5 ppg, 5.5 assists per game).

Guards Jennifer Azzi (10.8 ppg) and Sandy Brondello (13.3 ppg) lead Detroit, which has gotten a boost from forward Wendy Palmer. The former University of Virginia star has been explosive since she came to the Shock in a trade with Utah on July 29. She has had double-doubles in her last five games, averaging 17.3 points and 12.3 rebounds.

In the West, the Sparks, with the second-best record in the league behind Houston, and the Monarchs also split their regular season series.

The Monarchs suffered a key loss when center Yolanda Griffith, who was second in the league in scoring (18.8) and first in rebounding (11.3), injured her right knee in a game against Charlotte on Aug. 13 and had season-ending surgery.

"Our depth is weakened," Monarchs Coach Sonny Allen said.

Allen turned to Tangela Smith to fill the void, and she responded by averaging 16.1 points and 7.2 rebounds over her last six games.

"I couldn't ask for any more," Allen said.

Sparks Coach Orlando Woolridge said his team is preparing for tonight's game as if Griffith is still in the Monarchs' lineup.

"When you have a great player out of your lineup, the other players are a little more focused and they give a little more effort," he said. ". . . They tend to match up well against us. If you look at the two teams, we play a very similar style of basketball. We are very aggressive on the defensive end. We like to get out and run in the open court."