Knee-buckler
What is knee-buckler in baseball?
The knee buckler is any curveball flying sharply, freezing the batter that comes to the baseball. This starts directly on the batter, embraces its knees with fear and then moves to the hit area. The knee-buckler usually makes the knees bend and weak the hit. It touches only newbies. The experienced players use the backward or side-by-side motion to avoid that effect.