Of course, Koufax compiled his lifetime total in a much shorter career than Pettitte's. It took Koufax just 2,324 1/3 innings to reach his mark, pitching for the Dodgers from 1955-66; Pettitte entered play on Wednesday with 3,235 1/3 career innings.
Once Pettitte moves past Brown, Dennis Eckersley holds 38th place on the all-time strikeouts list with 2,401.
Bryan Hoch is a reporter for MLB.com. Follow him on Twitter @bryanhoch and read his MLBlog, Bombers Beat. Adam Berry is a reporter for MLB.com. Follow him on Twitter at @adamdberry. This story was not subject to the approval of Major League Baseball or its clubs.