How many knights?

Slightly different from chess but not less amusing I figure. On a chessboard, how many, say, white knights does it at least take to capture a black knight? Initially, no two knights of different color are in position to capture the other of the two. No other pieces than knights on the boards and no 'stalemate'. 

Perhaps a sequel to this problem would be to find the least number of identical pieces white would need to capture any black piece for all pieces.

first one is white to move(Nf4)  and second one is black to move.

Thanks for thoughts, Robert. Those the best-case scenarios, but you can't generalise 2 for all cases. 

kaynight, yes, as desired in description.

3

5

3 seems low. 'Stalemate' was achieved empirically using 4 in 1 of 2 games. 5 seems plausible, but since we require a catch, I can't exclude 6 (3 for both colors of fields). How did you both find the numbers?

Using Zillion of Games

I think 4 knights is the minimum, seeing a knight with maximum activity has 8 possible squares and you'll need a knight for every 2 squares to block.