Lefty Grove? He was 20-2 on July 25, 1931. He finished the season with a
record of 31-4.
Jack Chesbra
There are hundreds of pitchers that accomplished this feat.
Sandy Koufax (27 wins)
Chris Capuano
In 1968, Tigers' pitcher Denny McLain ended the regular season with a record of 31-6. He is the last pitcher in MLB history to win 30+ games in a season.
BiG Ed Walsh ~ Chicago White Sox ~ 41 games
Old Hoss Radbourn way back in 1884 won an amazing 59 games according to Baseball Almanac.
Through the 2008 season, that is Mordecai 'Three Finger' Brown who won 29 games in the 1908 season.
a pitcher's record for the season is his wins, then losses for example, if a pitcher won 15 games and lost 10, then his record would be 15-10
Babe Ruth won 94 regular season games (and 3 World Series games) as a pitcher and hit 714 home runs.
Jim Bagby won 31 games for the Indians in 1920.
Cardinals Dizzy Dean in 1934, 30 victories.