Head-to-Head
Overview
Jan Kumstat and Sung Nam Ji have met 1 time so far, all in 2026. Jan Kumstat leads 1–0. Their first encounter was at the 2026 Prostejov, won by Jan Kumstat.
By surface
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Jan Kumstat and Sung Nam Ji have met 1 time so far, all in 2026. Jan Kumstat leads 1–0. Their first encounter was at the 2026 Prostejov, won by Jan Kumstat.