In a 2v2 competition with 10 different players. How many different permutations of those 10 players are there?


My guess at the formula would be:
1/k^2(n!/(n-k)!)
Where n is the number of players and k is the type of tournament.
Which would give the number of combinations as:
315


But I dont think this solution is correct.

Can anyone help me out?
Thanks.