Armed with a big-breaking curveball, an underrated fastball and a great pickoff move, Flanagan strung together a decade of formidable pitching after losing his first five major-league decisions. From 1977 to 1987, he started more games (334) than any other AL pitcher and posted a .500 or better record each season from 1977 to 1984. His 1979 Cy Young Award-winning campaign saw him lead the majors leagues in wins with a 23-9 record while tying for the AL lead with five shutouts. He finished sixth in MVP voting, and was honored as Graduate of the Year by the Junior American Legion Babe Ruth programs. That October he won the first game of the World Series, but lost Game Five when he was moved up in the rotation in a controversial move by manager Earl Weaver.
Flanagan suffered a severe knee injury in 1983 (though he returned to win 12 games and make a pair of post-season starts) and a torn Achilles tendon in 1985, costing him big chunks of both seasons. Struggling in Baltimore, Flanagan found new life after getting traded to Toronto during the 1987 stretch run. The Blue Jays were no doubt glad to acquire him, as he owned more wins (17) and innings pitched (208) against them than any other hurler. After starting 30 games for Toronto in 1989, he was released when he got off to a slow start the following season.
Flanagan re-invented himself as a highly effective set-up man upon rejoining Baltimore in April 1991, recording three saves and a 2.38 ERA in 64 appearances. On July 13th, 1991, he pitched the seventh inning of a four-man tag-team no-hitter against Oakland, a game started by Bob Milacki and completed by Mark Williamson and Gregg Olson. He also threw the last pitch by an Oriole in the final game at the club’s longtime Memorial Stadium home that October. Bridging two eras of Baltimore baseball, Flanagan stuck around for one more season when the Birds moved into their news digs at Camden Yards.