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

With or without cutting the deck in-between each shuffle?
In Shuffling Cards, 7 Is Winning Number

The New York Times