i want to try a different grip on spare ballto limits the chance for the ball to change direction. like chris Barnes. Is that something call a grip-and-release.
I've read Ted Thompson's PBA tech talk.

Now, i'm having question what should i start with.

my current stike ball specs. It's a relaxed grip.
 

 
    < 3/8               0 >
1/4^  @@@              @@@  ^ 1/4
      @@@              @@@
       \                /
        \              / 
         \            /
        4 1/16      4 1/16
           \        /
            \      /      
             ^ 3/16
              @@@@@
        < 1/8 @@@@@
              @@@@@

any expert can help me with this.
how much longer in span
and the pitch of thumb
thanks so much

I can't really offer you an answer to your question.  I can tell you what works for me.  My spare ball is drilled a 1/16 longer than my strike ball.  I also have a lateral thumb pitch of 1/8 under palm instead 1/8 out like my strike ball.  I have no problems killing it so it does not hook.

Andrew
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