Ball motion is commonly broken down into sequential skid, hook, and roll phases. As the ball travels down the lane in the skid and hook phases, frictional contact with the lane causes the ball's forward ("translational") speed to continually decrease, but to continually increase its rev rate ("rotational" speed). Especially as the ball encounters greater friction in the last ≈20 feet (approximate) of the lane, the ball's axis rotation (side rotation) causes the ball to hook away from its original direction. Concurrently, lane friction continually decreases the angle of axis rotation until it exactly matches the direction of the ball's forward motion, and rev rate (rotational speed) increases until it exactly matches the ball's forward speed: full traction is achieved and the ball enters the roll phase in which forward speed continues to decrease.