Snap - continued.

Well the obvious strategy is to play red - that way you are guaranteed to win £1 every hand, and you could win £10.  Problem is of course that your opponent is equally capable of working that out and so the likelihood is that you will both play red every time - boring.  Of course, if you both play black you could triple your winnings, and this is where it becomes interesting.  After five hands you are allowed to talk to each other, and you could both agree to play black.  But now the question is - can you trust your opponent, and equally can they trust you?  Because if you know, or think you know that your opponent is going to play black, you can play red and potentially win £10.  This is in fact a variation on what is known as "The Prisoner's Dilemma" - a situation where co-operation is more beneficial, but leaves you open to treachery.  There's no right answer - it's just an interesting conundrum.