Bullets are fast. Arrows are slow. Failing to take that into account when you shoot at a moving buck can lead to a bowhunting debacle. If you want to place your broadhead accurately, you need to bring that buck to a stop.
Illinois hunter Jason Sanders shot what appears to be the largest main-frame, typical ever killed by a hunter under fair chase conditions. Preliminary scores say the buck nets inches. The current world-record typical 8 is inches.