I'm not entirely sure I placed this question in the right place, but I tried to locate the closest category.

I am building a memory game in a web programming language. I have come to the point where I need to calculate a score for a game. The score needs to be calculated after the user finishes a game.

The factors I want to be involved are:
-Number of turns
-Time (length) of game
-Number of cards to match in the game (maybe probability based)

Any math gurus out there have an effective algorithm for generating a score?

Thanks in advanced!