The O'ahu Interscholastic Association postseason baseball tournament promises to be a hotly contested "arms race" starting with tomorrow's first round.

Solid pitching — featuring outstanding arms on almost all 12 teams — has been the theme in both the Eastern and Western Division regular seasons.

"I think this year there's more quality pitchers overall," said Kailua coach Corey Ishigo, whose Surfriders won the East with a 9-1 record. "There were a lot of close games, and that's how the postseason is going to be, too. It might come down to who gets the breaks and who makes the most of those breaks. It's going to be tight, because all 12 teams are good."

Longtime 'Aiea coach Ryan Kato, whose Na Ali'i (9-1) won the West, said the OIA's quantity of good pitchers was at its highest level in years.

"I don't think I've seen this many quality arms in a long time," Kato said. "It seems like everybody has at least one, so I think it balances out the league. The games will be closer, and you just have to hope the ball will bounce your way."

Several of the regular-season games were decided in that fashion, resulting in very little difference between the seeded teams.

Moanalua, for example, features one of the state's best pitchers in senior left-hander Kekoa Lee, but a couple of hard-luck losses has Na Menehune (6-4) seeded No. 6 in the East.

They play at West No. 3 Pearl City (7-3) tomorrow.

Against Kailua on April 4, Lee threw no-hit ball for five innings before an error led to the Surfriders tying the score at 2-2 in the sixth. After another error in the bottom of the eighth, Kili Vierra hit a two-run homer off Lee to lift Kailua to a 4-2 win.

The next week, Lee was locked into a scoreless pitching duel with Castle's Pulama Silva when a two-out error in the bottom of the fifth inning led to a three-run homer by Lyle Kitagawa for a 3-0 Knights victory.

A couple of bounces the other way, and Moanalua would be 8-2, enjoying a first-round bye.

"The West was very similar," Kato said. "Just one pitch could sway the outcome. But that's good, because it gets you battle-tested and experience in pressure situations. It gives us an idea of what the playoffs are going to be like — every pitch, every play is critical, so you can't take a pitch off and you have to stay focused throughout the whole game."

Almost every pitch in 'Aiea's 1-0 victory over Mililani on April 14 was pressure-packed, and Na Ali'i ace Randy Castillo threw 130 of them in a 10-inning, complete-game effort.

Castillo, a hard-throwing 6-foot-2 right-hander, scattered seven hits in that game and struck 12, walking two. 'Aiea has another solid starter in Cody Aquino.

Kailua does not have a strikeout artist like Castillo but it does have two efficient starters in lefty Preston Nakata and righty Vierra. Marcus Mathews has contributed strong relief.

"We've stressed 'team' this year, even more than usual because we don't have any superstars," Ishigo said.

West No. 2 seed Mililani (8-2) has three right-handers with blazing fastballs — Dustin Antolin, Richie Mariano and Joey Aquino.

East No. 2 Roosevelt (7-2-1) has a top pitcher in Keoni Manago. East No. 3 Kalani (7-3) has one of the league's hardest throwers in Micah Takahashi, who has slowly come back from a back injury.

With all of these quality pitchers and teams, one thing seems certain: the five teams that earn state tournament berths will have earned it.

"The league has gotten better, and we'll be well-represented," Ishigo said.

Kato agreed.

"There aren't any Cinderellas, because everybody is playing at a high level," he said. "That's good for the OIA."

Reach Wes Nakama at wnakama@honoluluadvertiser.com.