Dennis, the reason to carry a spare ball is to take out the lane condition when picking up spares, especially corner spares. It has been said that the only reason to throw a hook at all is to take out the 5 pin. The shortest distance between two points is a straight line. If you can hit a target consistently, then the plastic ball is the best for the experienced bowler. I know that Norm Duke can change his release to pick up any spare he chooses. Not everyone can do that. It is much easier to keep the release the same and use a ball that will not hook unless the lanes are bone dry. I am the best spare shooter on my team, mainly because I am the only one who doesn't try to hook the ball for each of my spares. So, it doesn't matter if the lanes have light oil or heavy oil, my system, my targets, my ball speed, my release, all stay the same.
I'm not sure if you were trying to make a different point and I just didn't understand. If so, then accept my apology. If not, then this is the reason for using a plastic ball for spares. But I do know a guy at my job who is a better spare shooter than I and he uses his strike ball ( but he throws it straight like Norm Duke ), so whatever floats your boat.
A Storm is coming.
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