John811,
Here again is BT table.
Span.......Pitch
4 pitch = 1/8 forward
4 1/4 pitch = 0
4 3/8 pitch = 1/16 reverse
4 1/2 pitch = 1/8 reverse
4 3/4 pitch = 1/4 reverse
4 7/8 pitch = 5/16 reverse
The concept is ever 1/8 of span past 4 1/4 = 1/16 of added reverse pitch.
Ever 1/8 of span less than 4 1/4 = 1/16 more forward
This is based on Bill Taylor's famous 63 degree test. Angle of top front of fingers to top front fingers drawn to top front of thumb and then thumb angle drawn thru the surface of the ball(straight lines) is approx 63 degrees for all bowlers with standard thumb flexibility. About 105 degrees.
He then added general rules that if thumb was short(under 2 1/4") or dry or bowler was a dropper then subtract 1/8 reverse or move forward 1/8 from tables.
As a shorter dryer thumb the table with 1/8 forward almost works perfect for me.
Longer thumbs, wetter thumbs and stiffers thumbs usually add 1/8.
Two warnings.
1. The rule above practiced by some of our top experts(Magic Carpet and Jeff Mop whom I both respect greatly). Can result in funny results.
Example .... Yesterday I go to center. Guy is practicing before scratch league. Just before release he is having his upper body dip noticeably and on every throw he is lofting and nearly hanging in front of thumb. Still getting good hook with this dip.
I ask my friend the house driller, have you seen this? Yep. I ask guy is that a new pitch or span for you? NOPE! Had it for awhile. What are pitches I queried? He said I'm 1/4 forward and the span is almost 5 .... alittle over 4 3/4. HMMMMMMMM.
?? I say nothing. Let's see, 4 3/4 Bill Taylor says 1/4 reverse he is 1/4 forward hmmm that is only a 1/2 inch difference.
Now I will tell you he MUST dip or that ball is going thru the roof! At this point either a weakening of the holding pitch(add reverse) by 1/8, 3/16 or so is necessary.
OR a dramatic increase in front bevel!
Agreed for many the Bill Taylor tables are a little more reverse than today's top bowlers are using. Except those with stiff thumbs. Only 90 degree or less flexibility.
2. Second caveat is nerve damage. A bunch of guys in my former location decided to move their thumb pitches forward 1/4 from their current location while not changing span. SOme had custom thumbs. Several came to me and said...Do YOU know why I've got this black mark near the top of my thumb and also some pains in it??? NoooooOOOOOOO! kidding. YOu see a dramtic move forward without a span change(shortening) makes the edge of the thumbhole sharper. Think of a righ turn for your car that is 90 degrees versus one that is 75 degree turn, greater than right angle! That is what your thumb must now do. Be careful that black mark and tingling can cause near permanent nerve damage if left unattended.
Either move forward very slowly more like 1/8 at a time and also increase front bevel if there is any hanging or pain! Also realize 0, forward or reverse are not good or bad. Everything should be referenced instead to forward of the magic 63 degree table or reverse in relation to the 63 degree table.
For example a good bowler shoots an 800. YOu go and say, hey do you use forward or reverse. He says, Ummm I use forward. His span is 4 and yours is 5. You go to your driller and say, "I want to use forward"! What your didn't know was that he was using 1/16 forward which is 1/16 more reverse than tables.
You on the other hand will now have to move 3/8 forward of tables to get to forward. Maybe the right move for you is to 5/16 REVERSEs.
Bon Appetit.
Hope this helps someone!
REgards,
Luckylefty
