I would start by checking your span yourself. Put your thumb all the way into the ball and comfortably (not stretched) lay your fingers overtop of the finger holes. The first crease in your fingers (joint) should be near the center of the grip hole... or the edge of the grip should fall about 1/2 way between your first joint and second joint of your fingers. PM me your email address again, and I will forward you a copy of Mo's article explaining this in detail. Most drillers (including ones from my proshop) tend to over estimate spans...they want to place the first joint of your finger at the edge of the grip.. which gives a span that is too long.
Next order of business is determination of lateral pitch. Personally, I think it is jusr preference based upon comfort, but in the Bill Taylor manual it states that lateral pitches can be used to raise or lower your track.. the further right lateral pitch (assuming a right handed bowler), the higher the track... so I guess left lateral pitch leads towards coming around the ball or increasing axis tilt. He uses the coke bottle test (I like the aquafina water bottles)... thumb points to middle finger = 1/8 right, ring finger = 3/8 right, pinky = 5/8 right... (by the test I'm 1/8 right, but prefer and use 1/8 left)..
Once lateral is determined, determine the appropriate forward/reverse thumb pitch based upon span. Strictly going by Bill Taylor, the forward and reverse pitch is based upon a span of 4 1/4" (0 pitch). Shorter than 4 1/4 uses forward and longer uses reverse (1/2 the difference between aactual and 4 1/4"). The amount for forward pitch in the thumb 1/16" is correct for your span of 4 1/8" (assuming an average bowler). He states to add reverse for a long thumb and for a tacky (sweaty) thumb and add forward for shorter and/or dry thumb.
These are pretty decent guidlines for fitting a person. And generally what I use.
You stated that sometimes you have "bounced" the ball. Usualy that's a sign of the thumb clearing too quickly... and dropping the ball...if that's the case, it might just be an issue of thumb hole size (or actually requiring more forward pitch to help hold onto the ball)... For me, front to back my thumb is 29/32, but side to side its closer to 15/16.. so I am forced to drill 29/32 and oval the sides quite a bit to fit...
Generally speaking, shorter spans allow you to get out of the ball quicker and generate more revs. Longer spans tend to "lock" your hand into the ball...
S^2
--------------------
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-
Strapper SquaredAlias GeneratorEdited on 2/7/2006 1:12 PM
Edited on 2/7/2006 1:17 PM
