He earned the nickname "Brudder Bill" because he was teammates with his older sibling, Jack Gleason, on several amateur and professional baseball teams.

[1] His most productive season came in 1887, when he posted career numbers in batting average (.288), runs (135), hits (172), and on-base percentage (.342).

While Gleason was considered a gentleman off the field, he was loud and aggressive on the baseball diamond, often hurling continuous insults at opposing players or using his spikes on the basepaths to break up double plays.

An 1885 Sporting Life article suggested that if Gleason broke a limb or his neck, "not a ball player in the American Association would feel the slightest regret.

With a tie game in the ninth inning, and with darkness setting in, Kelly told his Reds teammates to stall time.