Today, if a relief pitcher pitches in two consecutive games there is concern about his arm. He will usually not pitch for one or two days after that.
Matt Belisle led all relief pitchers with 92 innings pitched for the Colorado Rockies last year. It took him 76 games to pitch those 92 innings.
Let us go back to 1952
After a long career in the Negro Leagues, and two seasons with the Cleveland Indians, Hall of Fame pitcher Satchel Paige was now pitching in relief and sometimes starting for the St Louis Browns.
Less than three weeks before his forty-sixth birthday, June 20 1952, Paige relieved in the seventh inning of a game against the Washington Senators and pitched ten shutout
innings . He allowed only five hits. The game ended in an eighteen inning 5-5 tie.
Less than two weeks later, 7/1/52, Paige pitched 10 /2/3 innings in relief against the Cleveland Indians. In the first ten innings he did not allow a run. He lost the game when he allowed two runs in the nineteenth inning.
On 8/6/52, Paige started against the Detroit Tigers and pitched a twelve inning complete game shutout, winning 1-0!
In those three games Paige pitched 32 2/3 innings, allowing only 20 hits and two runs.
A starting pitcher going ten innings in a game is now unheard of. Paige did it once as a starter and twice as a reliever in the same season.