I have been thinking about this rule change a lot since I have a very good customer that does not use his thumb the vast majority of the time. At first glance, it may appear that these “thumbless” bowlers were using the thumb hole (TH) to their advantage as an extra weight hole (WH). However, consider this . . whether you have 2, 3, 4, or more holes in a ball, those holes do not effect anything about the ball until it is released. At the moment of release, don’t all the holes become WH’s? Although finger holes (FH) and TH are used for gripping (for us traditional style bowlers), at the moment of release they in essence become WH’s. Their location, size, and depth (in relation to the bowlers PAP) have an effect on the core and reaction dynamics of the ball traveling down the lane. Ex: deeper FH’s will typically raise the Diff. which increases the flare potential.
With this rule change, the “perceived” advantage would now go to the traditional bowler who uses his/her thumb because they could have 4 holes in the ball; 2 FH, 1 TH, & 1 WH. The thumbless bowler would only be allowed to have 3 holes total; 2 FH & 1 WH. This all assumes the bowler uses only 2 FH’s although more is permitted. So if this rule change was done to promote fairness, it seems, on the surface, to have holes in it.
Personally, I do not care either way. You still have to be accurate & repeat shots. Just some food for thought and my $.035 ($.02 adjusted for inflation). Besides . . don’t matter where you put the holes or how big they are, ALL Motiv balls react great !!