There have been occasional exceptions to Pettitte's domination of the Birds. The most recent installation of the Eutaw Street Chronicles recounts one of those exceptions when the O's scored nine first-run innings against him on April 30, 1996. Otherwise, it's been lights out.
From The Sun:
Pettitte, 37, improved his career record against the Orioles to 26-6 with a 3.56 ERA in 39 appearances (37 starts). He is tied with Catfish Hunter for the second most victories all time against them. Another former Yankee, Whitey Ford, heads that list with 30 wins. Pettitte (12-6) was so dominant that in retiring the first 20 Orioles he never went to a three-ball count, and he went to a two-ball count just eight times.There's no denying Pettitte's abilities. However, a primary reason that he is tied for the second-most victories against the Birds is that our own pitching has been so bad during the majority of his career.
As evidence, compare Pettitte's career numbers against the O's with the numbers he's posted against the Red Sox. We can hit like Boston, but we can't pitch like them.
The lefthander has started 38 games against Baltimore, 35 against Boston. He's won more than 80 percent of the former games, 65 percent of the latter. The difference, however, isn't team hitting.
Pettitte has a slightly higher career ERA against the Red Sox (3.76) than he does against the Orioles (3.65), but otherwise the numbers largely favor the O's bats over Boston's.
Pettite has given up twice as many home runs to the Orioles (18 to 9 for Boston), has a slightly higher WHIP (1.426 to 1.406), strikes out fewer batters per nine innings (5.1 to 7.1), and has a lower strikeout-to-walk ratio (1.56 to 2.41).
Both teams' batting numbers against Pettitte are roughly equivalent (the Orioles numbers are listed first): .275 average vs. .278 average; .338 OBP vs. .334 OBP; .384 SLG vs, .385 SLG; .722 OPS vs. .719 OPS.
Nevertheless, Pettitte is 25-6 against the Orioles and 17-9 against the Red Sox. The difference isn't the hitting, but rather the pitching. The O's simply haven't had the necessary arms to match Pettitte's consistency throughout his career.