Breaking the Grip: Releasing or significantly altering the interlocked hand position; Using Other Fingers: Using fingers other than the thumb to assist in pinning; Early Start: Beginning before the opening chant is complete
Why people argue about this
People often assume that you can use other fingers besides your thumb in a thumb wrestling match, thinking it's just about who has the strongest thumb. But actually, the rule clearly states only thumbs are allowed, and using others is penalized with a warning on first offense, followed by a forfeit of the round if done again. Confusion arises because many forget this detail entirely.