Howell was one of the hardest-throwing relief pitchers of the 1980s, despite an up-and-down career. He led the AL in strikeouts per inning in 1984 with the Yankees and became the stopper for the A's and the Dodgers. He had his best season in 1989 (5-3, 1.58 ERA, 28 saves). In between, he endured horrible collapses, with ERAs above 5.00 in both 1983 and 1987. He was the losing pitcher in the 1987 All-Star Game
Howell achieved national notoriety with the Dodgers in the 1988 LCS against the Mets. In Game Three, played in a cold rain, he was ejected for having pine tar on his glove. He was suspended: at first for the next three LCS games, but ultimately, after an appeal, for two. He had already lost Game One in the ninth inning on the first run he had surrendered since August 11. In the World Series, his inconsistency continued;
he surrendered a game-losing ninth-inning homer to the A's Mark McGwire in Game Three, but came back the next day to save Game Four with 2-1/3innings of scoreless relief.