Blackjack Strategy Video Source & Information:

Kudos for rockstar for making almost everything realistic in this game even the difficulty of the minigame blackjack. it can really happen in real life. thats why i tried to play this using the famous “Blackjack Basic Strategy” that pretty much lets you play the best hand possible.

Heres the link Guys

https://wizardofodds.com/games/blackjack/strategy/4-decks/

feel free to comment below for questions or sharing experience
otherwise suggest any guide that i can make for you guys.

Source: YouTube