This is according to Retronaut.
The year is 1886, and the gentleman is Boston Beaneater pitcher Charles "Old Hoss" Radbourn. This photo is a pre-game snap before a game against the New York Giants (thus, the finger, I imagine).
In the two-pitcher rotation era, Radbourn compiled a 309–195 career record. In 1884 he won the National League's pitching Triple Crown with a 1.38 ERA, 60 wins and 441 strikeouts.
A butcher by trade, Radbourn was once asked if he ever tired of pitching so often. He replied:
"Tired out tossing a little five-ounce baseball for two hours? I used to be a butcher. From four in the morning until eight at night I knocked down steers with a 25-pound sledge. Tired from playing 2-hours a day for 10 times the money I used to get for 16 hours a day?"
Take note, six-and-out starters of today.