RHP Edward "Big Ed" Augustine Walsh, who debuted in Major League Baseball MLB) for the American League (AL) Chicago White Sox on May 7, 1904, pitched 14 seasons in MLB -- all but one with the Chicago White Sox -- with a career Win-Loss record of 195-126 in 2964 innings pitched in 430 games (315 games started and 250 complete games). Walsh hold the MLB record for the lowest career ERA, posting a career ERA of 1.82.
Eliminating pitchers who may have thrown only a few innings or games during any particular year, the lowest ERA for a season belongs to Bob Gibson (of the St. Louis Cardinals); in 1968 his ERA was 1.12 . . . Dwight Gooden (of the New York Mets) would have had the next-lowest ERA, that being 1.53 during the 1985 season.
Sandy Koufax has the least for a first round inductee.
Ed Walsh with in ERA of 1.82
Fernando Rodney in 2012. 0.61 ERA
Roy Holliday Roy Holliday
ubaldo jimenez Colorado rockies
In 1914 Dutch Leonard had a 0.96 ERA
Bob Gibson, St. Louis Cardinals. He went 22-9 that year. Amazingly, he lost 5 games that year by identical 1-0 scores.
Pedro Martinez of the Boston Red Sox led MLB in ERA in 2003 with 2.22.
Jake Peavy of the San Diego Padres (2.54)
That was Bob Gibson, whose 1.12 ERA remains the lowest for any starting pitcher since Dutch Leonard in 1914, and the fourth-lowest of all time, dating back to 1876. In that year Gibson pitched 13 shutouts -- since 1998, no MLB starting pitcher has had 13 complete games!
Season record would be Spud Chandler
That was Pedro Martinez of the Boston Red Sox at 2.22.
Babe Ruth, pitching for the Boston Red Sox had the best ERA in 1916. It was 1.75. That's a low ERA for people not familiar with the game.
The club record is 1.69 accomplished by Nolan Ryan in the 1981 season.