Understanding Entry Angle
Last month we discussed the importance of entry angle for pin carry. This month, we'll look at where the ball needs to be to create that entry angle.
We have long believed, and USBC has confirmed, that an entry angle of about 6 degrees improved strike percentage. USBC studies also showed that the best strike percentage occurred when the ball enters the pins at the 17.5 board.
At left you see the trigonometric formula for determining what the entry angles really mean in terms we actually can use on the lanes. The formulas assume that each board is 1" wide (although actually each is about 1.05" wide, so that 39 of them equal the 41" wide lane surface). At the edge of the lane, the ball is 17.5 boards from the entry board. If we know how far the ball is from the pins, we can determine what board it should be on for any given entry angle.
The diagram at right shows exactly where on the lane the ball needs to be to create 4, 5 and 6 degree entry angles. You can see that you cannot even approach these entry angles with a straight ball. You'd have to stand a lane or two over to get on those lines. It also shows that a straight ball from the gutter corner enters the pocket at less than 2 degrees; a shot over the 2nd arrow gets you less than 1 degree.
Clearly, hooking the ball at the pocket is the only way to get the 4-6 degree entry angles necessary for the best pin carry. How much hook, and where it occurs, makes a lot of difference in getting those angles.
Next month, we'll look at where your break point needs to be down lane to get those entry angles, and the kind of ball motion you might want to consider to help get there.
