Seven standard "riffle" shuffles are needed to effectively randomize a 52-card deck.

https://lemmy.dbzer0.com/post/34667105

Seven standard "riffle" shuffles are needed to effectively randomize a 52-card deck. - Divisions by zero

Lemmy

I always thought riffle shuffles were super ineffective. Most of the cards remain in each others vicinity. What is a better way?
It’s the best way, period. Even as inefficient as it may seem, inexpertly done, seven shuffles and you’re good.