Although two slots in the District 1 Class AAAA softball playoffs won't get filled until Monday night - the weatherman willing - the playoffs should open Tuesday with 16 of the 24 teams in action. The top eight teams in the field drew first-round byes.

The Nos. 1 and 4 slot are to be decided Monday night with perennial powers Pennsbury and Neshaminy going at it in a game that's part of a doubleheader at Bristol. The doubleheader will benefit the fight against cancer. The other half of the twin bill pits Class AAAA Truman against Class A Bristol.

"We're committed to playing the [benefit] games," said Neshaminy coach Dave Chichilitti, noting that they were postponed several times because of rain. "The doubleheader is the crown jewel of high school softball in Bucks County."

Not only does it marks the final game of the regular season for the teams, but the Neshaminy-Pennsbury winner will get the top seed in the district playoffs; the loser will be No. 4. Both teams have one loss in the Suburban One League National Conference race. The Redskins (15-2 overall) were beaten by the 15-2 Falcons, 5-3, in their first meeting despite having more hits. Council Rock North beat Pennsbury, 9-1.

Here's a look at how Monday's first-round matches shape up, with seedings in parentheses:

Perkiomen Valley (17) at Central Bucks East (16). This is a tough one to call. East plays in the very tough Continental Conference of the Suburban One League. The Vikings might have a slight advantage with pitcher Tori Marcavage, who has more than 500 strikeouts in her career.

Interboro (24) at Haverford (9). The Bucs had to beat Chichester on Saturday in their regular season to win the Del Val League title and get into the playoffs as the last seed. The Fords finally won out in a wild Central League race.

Norristown (21) at Downingtown East (12). The Cougars lost the race with Downingtown West to be the Ches-Mont League's No. 2 team. Sydney Robey been a pitching and hitting leader for the Whippets, who started 6-0 but then lost three straight before righting themselves. The Eagles have some young pitching and are led offensively by fleet centerfielder Sammi Kidd.

West Chester East (20) vs. Wissahickon (13). East has been unpredictable at times, but pitcher Brianna Andraos should be able to get the support she needs to beat the higher-seeded Trojans and pitcher Katie Ziegler. The winner draws Monday night's Neshaminy-Pennsbury winner in the second round on Wednesday.

Plymouth-Whitemarsh (18) at Upper Darby (15). The Royals have had a very respectable season, with freshman pitcher Savannah Nierintz being a key. The Colonials finished third in the Suburban One League American Conference. This is another game that could be a toss-up. The winner gets No. 2 seed Hatboro-Horsham in the second round.

Penncrest (23) at Downingtown West (10). The Whippets, who won their first six games, then lost three in a row, had to beat West Chester Henderson Saturday to land the Ches-Mont League's No. 2 seed. The Whippets will look to pitcher Casey Herring to lead them. The Lions are the No. 4 team from the Central League.

Garnet Valley (19) at Spring-Ford (14). This is another close call. The Jaguars are not the powerhouse of recent years but do have a strong hitter in Mary Schlosbon. The Rams put together a 12-game winning streak only to lose their last two PAC-10 games, one of them the league championship to Boyertown. They had beaten the Bears twice earlier.

West Chester Henderson (22) at Council Rock North (11). The Indians, working to revive a program that had fallen on hard times, should be motivated enough to beat Henderson. The Warriors are capable of pulling off a surprise behind pitcher Lauren Butts.