A look at tonight's playoff matchup between Aberdeen and Tri-City

ABERDEEN, Md. - It is a big night at Ripken Stadium. The short-season Single-A Aberdeen IronBirds play in the first playoff game in the team's 12-year history. The IronBirds host the Tri-City ValleyCats, a Houston Astros affiliate, in the best-of-three league semifinals. Tri-City, which finished with the better record, is the higher seed and will host Game 2 Saturday at 7 p.m. and Game 3, if necessary, on Sunday at 5 p.m. Aberdeen finished 40-32 to win the McNamara Division title. The IronBirds have won five in a row, nine of 12 and went 20-11 in their last 31 games to charge toward the playoff berth. Sebastian Vader, a 21-year-old right-hander, will start tonight for Aberdeen. The Orioles' 18th-round pick in 2010, went 7-3 during the regular season with a 2.43 ERA, which was eighth-best in the New York-Penn League. He set a franchise record for most wins in a single season by a right-handed pitcher. The ValleyCats will send Michael Feliz to the mound with a 4-2 record and 1.96 ERA. The 19-year-old right-hander from the Dominican Republic led the league in ERA and finished third with 78 strikeouts over 69 innings. Right-hander Hunter Harvey (0-1, 2.25 ERA), the O's 2013 first-round pick, is expected to pitch Game 2 for Aberdeen tomorrow night. The IronBirds went 4-2 against Tri-City this season, taking two of three both at home and on the road. The winner of this series meets the State College-Jamestown winner for the league championship in a best-of-three series. There will be a limited number of rally towels given away to fans as they enter Ripken Stadium tonight, as well as a postgame fireworks display. Tonight's Aberdeen lineup: CF Mike Yastrzemski DH Jeff Kemp 1B Trey Mancini LF Conor Bierfeldt C Austin Wynns SS Jared Breen 3B Federico Castagnini 2B Justin Viele RF Manny Hernandez Orioles director of player development Brian Graham, director of minor league operations Kent Qualls and director of baseball administration Tripp Norton are among the members of the Orioles front office expected to attend tonight's game. IronBirds owner Cal Ripken Jr. broke Lou Gehrig's record for consecutive games played on this date in 1995, so it seems fitting that his club's first playoff game is 18 years later, to the date, tonight in Aberdeen.