Vernon,
You ask a very or relatively complex question.
I'd guess that, in general, a ball is specific, MORE, to range of oil condition, than it is to a bowler. HOWEVER, it is also specific to a bowler's speed, almost more than any other release or delivery factor, such as, tilt, rotation or revs. (Can you see the complexity building already?)
General opinions (mine, and others, of course):
1. most balls will handle a condition and cover some parts of the one above (more oil) and some of the one below (less oil). IN GENERAL, a medium ball, say, like the Brunswick Brusier or the Columbia Detour will handle medium oil and a little (into) medium-light and little (into) medium-heavy oil patterns.
2. Then revs and ball speed come into play.
* If you have higher ball speed, you need a stronger ball (read, "grabbier") to play mediums, oR you will use the medium ball to play medium-light oil patterns.
* If you have lower ball speed, you need a weaker ball to play mediums OR your medium ball will play/be useful on medium-heavy oil patterns, just because it will grab earlier.
2B. Revs:
* if you have higher revs, then things start to get really complex. YOu have to balance your higher revs with ball speed. Higher revs create more AND earlier flare, so your medium ball may be able to be used on medium-heavy oil patters, YET, most higher rev players ALSO have higher ball speed. THus, the complexity gets kind of messy at this point. The proportion of ball speed to revs shows what balls can or can;t be used, and what drillings (generally weaker ones) can be used.
(Hell's bells, even my tiny brain is reeling now.)
Remember our Thursday session:
Vinnie with his slower ball speed & less revs, was able to use a White Dot.
Dave with his much higher ball speed could, if he was careful, use his Ultimate Inferno.
Jerry was able to use his Intense in the last 2 games, but I could not use mine (due to relase style or revs, I am not sure). Hard to "see" myself.
(Jerry had pin below ring finger, which is for early roll: I have pin next to ring finger, which is for more length.)
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"We get old too fast, and too late, smart."