He played in Major League Baseball from 1898 through 1918 for the Louisville Colonels, Pittsburgh Pirates, Chicago Cubs and Cincinnati Reds.

Leach led the National League in home runs in 1902 with six, and played in the first modern World Series in 1903 with the Pirates, hitting four triples to set a record that still stands.

During Leach's years in Pittsburgh as a regular and playing with stars such as Honus Wagner, the Pirates won the National League pennant four times and were World Series champions once.

Despite the loss, Pittsburgh owner Barney Dreyfuss could feel his vision of a World Series had been a success, since the public had come out in large numbers to watch the games with over 100,000 paying spectators.

The games had been hard-fought, with the players on both teams giving it their all, and the Pirates had proven to be a mighty foe, with stars such as Leach proving their worth on the field.

As a result of this and similar experiences, some historians credit Hoy with umpires using hand signals for balls and strikes and safe and out calls.

[9] In the fall of 1960, Leach appeared on the television program I've Got A Secret alongside Boston American Freddy Parent, as a commemoration of participating in the first World Series in 1903.