South Putnam (28-0) plays Union County (22-7) in the opener at 11 a.m. Saturday at the Forest Park Semi-State.
Senior pitcher Brooke Boetjer leads the South Putnam team, but a balanced offense will be the key to winning another regional.
Boetjer (19-0), who committed to pitch at Indiana University next year, leads the team with an astonishing 0.12 ERA. She has surrendered only two earned runs all season, while striking out 142 and walking 15.
Senior Emily Dabkowski is the Eagles' leading hitter sitting at .593, while junior Jenna Jones leads the team with five home runs.
Union County will counter with an ace of its own.
Senior Maggie Tidrow has been dominant in the post-season, having yet to give up a run in four games.
The left-hander struck out 16 and allowed only a single hit in the team's last victory, the school's first regional championship.
In March, Tidrow next year for Cardinal Stritch University in Milwaukee.
Offensively Union County has struggled in the postseason. In the sectional tournament they scored only three runs in three games. The Patriots exploded for 7 runs against Heritage Christian to win their regional.
The second game will likely have a more offensive flair. South Knox (19-8) will take on Switzerland County (10-16).
South Knox brings a powerful scoring team and will likely throw sophomore Lauren Keller.
Keller allowed one run in the sectional championship, then with the score tied in the bottom of the seventh, hit a walk-off home run to give her team a 3-1 win.
They defeated South Spencer 2-1 to win their region.
Switzerland County enters the semi-state event appearing to be a team of destiny.
After finishing the regular season 6-16, the Pacers have rolled to four straight wins and a regional title.
The team trailed 9-7 with two outs in the bottom of the ninth of the sectional championship game before rallying for the 10-9 victory.
They fell behind again in the regional championship, rallying from 3-1 down against Providence to win 6-4. It was their second regional title in three years.
South Putnam won semi-state at the same location last year before moving on to state.