He assured me that it really happened, but I reckon he was just pitching me a line.

他言之凿凿地说确有其事，可是我觉得他在说谎。

He was pitching the ball.

他正在投球。

Researchers can precisely measure previously unquantifiable aspects of pitching—everything from the angular velocity of the arm at the shoulder joint to tension on the knees and elbows.

研究者可以精确地测量出先前无法量化的各种有关投球方面的数——关节部位手臂移动角度的速度，到膝盖和手肘的张力。