Track Flare and Balance Holes

Now we find with the new two piece balls with reactive coverstock, that these weights only influence about 5% of the overall reaction of a bowling ball in motion. Top weight is sometimes used to some small degree for tweaking some layouts, but side weight, finger and thumb weight hardly affect the ball's path down the lane.

Positive side weight is usually reduced from between a half oz to zero in order to basically keep the ball legal, and also not alter the reaction desired. The distance from the PAP is the most important factor when laying out a ball for drilling. The second most important is the angle of the weight block to the track (1.30, 12.00 or 10.30).

This refers to the many tracks (of oil) that will appear on the ball in many layouts. This happens because the weight block tries to stabilise itself as the ball goes down the lane. We have to be careful to divert the track flare away from the holes. Generally speaking, the more track flare, the more hook or backend reaction created.

Using an Extra Hole or Balance Hole

Extra holes in the ball are now common place. Many layouts put the ball out of balance and beyond legal limits. An extra hole must then be drilled.

You are allowed one more holes than is required for gripping purposes. We generally put the hole on the bowler's PAP, 2" past the PAP or at six and three quarter inches from the grip centre. This maximises the construction for some benefit, or a smaller hole so as not to alter the ball reaction.

The distance of the hole from the grip centre is used by many drillers, hence references are made to 6", 7", 8", or 9" holes.

In the newer, high flare reactive bowling balls 8" or 9" holes are not now normally used, because of the risk that the track may flare over the extra hole.