Card Flipping

Alright, just to post because I haven't done so in a few days, I'll introduce a new problem. I first learned this problem (as with so many of my puzzles) from Bart:

I hold a deck of 52 cards, 26 of them are red, and the other 26 are black. I will flip cards face up off the deck one at a time until you tell me to stop. When you stop me, I will then flip one more card, if that card is black you lose the game, if it is red you win the game. You are required to stop me before I flip the last card of the deck. What is the optimal strategy to win this game?

As is my standard method, I'll post the solution next time.