According to baseball historian Bill Arnold, if these Orioles can win the American League East, they will have accomplished a pretty rare feat.
Only nine times in modern baseball history has a team trailed in its division by 10 games or more on July 18 and come back to win the title, with the 1995 Seattle Mariners being the last club to do so (while winning a one-game playoff with the California Angels).
The Orioles trailed the Yankees by 10 games on July 18 (and were a half game up on Tampa Bay Rays). But the Orioles and Rays won't claim the AL East record for such a comeback. The 1978 Yankees were 14 games behind the Boston Red Sox on July 18 of that year and eventually won a legendary playoff to capture the division flag (thanks to light hitting Bucky Dent's homer).
Three teams — the 1951 New York Giants, the 1978 Yankees and 1995 Mariners — tied for the division and had to win a one-game playoff to join the list. The St. Louis Cardinals franchise has done it three different times in its history.
According to Arnold, the list of teams to accomplish the feat were: The 1914 Boston Braves, the 1930 Cardinals, the 1942 Cardinals, the 1951 New York Giants, 1964 Cardinals, 1969 New York Mets, 1978 Yankees, 1993 Atlanta Braves and 1995 Mariners.