If you want to get your head spinning, read the rules governing no-thumb bowling, specifically the ball drilling rules.
You have to feel for those at the United States Bowling Congress charged with coming up with rules that fairly govern all situations!
The newest rules, which I detailed in this story, were enacted for the 2016 U.S. Open. They presumably stemmed from the growing popularity of &ldquo;Triangle&rdquo; or &ldquo;WiFit&rdquo; (aka &ldquo;Duo&rdquo;) grips that allow no-thumb...

The world’s No. 1 bowler and most famous 2-hander wants the USBC to enact rules that feature a trade-off and much simplification. Belmonte’s idea would forbid “flipping” grips for bowlers like himself who do not use their thumbs, while allowing no-thumb bowlers to use drilling layouts and weight holes the same as traditional bowlers.

Belmo ball drilling rule

Jason Belmonte calls for rule simplification: Ban grip ‘flipping’ by no-thumb bowlers, allow no-thumbers to drill under same rules as traditional bowlers