He bought a brand new deck of cards to use for the next Saturday's game. He left it in the plastic wrapping until time for the first deal, which would be his. Dad was going to make a show of how that game would be fair by opening the cards in front of the guys.
So Saturday night came, everyone sat down, and Pops pulls out the new deck. You can all see for yourselves, fellahs, that this is a new set of playing cards which are obviously untouched, he says, or something similar. He gets a knife and cuts the clear plastic wrap, opens one end of the box, and triumphantly fans out the red-backed poker cards for all to see. Well, they were red, except the one blue-backed card (which happened to be an ace of spades) amidst all the others. Sure, Bill, you don't mark deck.
Even Dad got a belly laugh out of that. As poker players might say about such things, 'What are the odds?'