William Kempner is a right-handed pitcher for the Miami Marlins.

In MLB, William Kempner has appeared in 7 games (10.0 IP) with a 0.00 ERA, a 0.50 WHIP, and 9.90 strikeouts per nine innings, on 11 strikeouts and 2 walks. In AAA, William Kempner has appeared in 37 games (48.2 IP) with a 3.51 ERA, a 1.32 WHIP, and 14.24 strikeouts per nine innings, on 77 strikeouts and 36 walks.

William Kempner's most recent tracked outing on netpitch was Jul 11, 2026 (MLB 2026).

Use the interactive dashboard above to break down William Kempner's pitch mix, velocity, command, sequencing, count leverage, and damage-risk trends across every tracked MLB and AAA appearance.