Poker, Blackjack, Old Maid... take your pick. A marked deck will make you an ace at 'em all.
For this cheat you need a Bicycle deck, a box cutter, keen eyesight and an excellent memory of the code. Essentially, you're carving a miniscule symbol for every card's value onto its back.
Phatus Magic's video breaks down the steps for an undetectable execution. Phatus' cheat is so good, you have to play it down. Don't be greedy though. Someone might catch on.
We admire this meticulous and anal tutorial.