He played most of his career between 1940 and 1948, winning the Hoofdklasse national baseball championship four times with SC Haarlem and Schoten.

[1] Considered one of the most dominant pitchers of his era (along with Han Urbanus), Dutch baseball historian Chris Kabout observed that "when you managed to get a hit against [De Mon], you had a starting spot in the Dutch national team.

An army officer who was a Major League manager in daily life invited Roel de Mon to come and play baseball in the US.

[citation needed] De Mon died in 1973 after serious heart failure, at age 53.

[5] Winners have included Charles Urbanus Jr., Harry Koster, Alexander Smit and David Bergman.