The main reason that people with no physical limitations use balls that weigh less than 16 pounds, which Shelley touched on in a way, is deflection.
"Back in the day," before resin (especially in the days of rubber and plastic), a bowler needed every bit of ball weight that he/she could get to avoid too much deflection in order to go through the pins and take out the 5-pin.
When resin balls came on the scene, people started seeing leaves like solid 9-pins, and more 4-9 splits than with rubber or plastic. Today's equipment is so strong off the end of the oil pattern that in some cases, 16 pound bowling balls do not deflect ENOUGH to get optimum carry.
That is why some people (even big ones) use 15 (or 14) pound equipment.
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RW (THB)
Edited on 3/20/2008 9:30 AM