Hans Bouwen pitched in the Hoofdklasse.
Bouwen debuted in the Hoofdklasse in 1961 with ADO. He was picked for the Netherlands baseball team in the 1961 Haarlem Baseball Week, the first Haarlem Baseball Week. He switched to Sparta and pitched for them from 1962-1965. The team won the championship in 1963. Bouwen then moved to Neptunus, which was then in the Dutch minors, and played for them in 1966-1967. He later taught young baseball pitchers. His daughter Saskia Bouwen played softball in the top Dutch league and his son-in-law Peter Herkemij has coached youth baseball.
Source: Obituary by Marco Stoovelaar