American Football Rules Approved Ruling 4-1-3:III

III. Third and 10 at the A-35. Quarterback A11 sweeps to his right and goes into a feet-first slide to give himself up. When he starts his slide, the forward-most point of the ball is at the A-44,
and when he comes to a stop the forward-most point of the ball is at the A-46. RULING: Fourth and one at the A-44. The ball is dead at its forward-most point when he starts his slide. [Cited by 4-1-3-r]