Clifford Luyk Diem, (born in Syracuse, New York on June 28, 1941) is a former Spanish Americanbasketball player. Luyk was athletic, talented, and possessed great low-post skills, highlighted by his trademark, old-school hook shot.
Luyk joined Real Madrid in 1962, and acquired Spanish citizenship three years later. Luyk retired in 1978, having won six Euroleague titles with Madrid's legendary club (1964, 1965, 1967, 1968, 1974, and 1978, despite not playing in the 1978 final). This record makes him unique, because he is the only player, who has won 6 Euroleague titles as a player with the same team. Luyk also won 14 Spanish Championships, 10 Spanish Cups, and 2 Intercontinental Cups.