Ko fight example from a pro game - 10

Starting position  

White has cut at

Standard  

Normally we capture the cutting stone but here White would save four stonesin sente and capture two in the process.

Ko - resolved  

In the game, skillfully creates a ko up to . Then takes the ko first, is the ko threat and resolves the ko immediately.

Ko fight  

Suppose responds, then recaptures. Whichever Black's threat comes next (conveniently chosen as a big point here), White enlarges the ko at . Black can hardly fight this ko and will (eventually) cover at . White can then connect with at in sente because below there's a liberty race going on.

Eventually White can return to Black's threat with while having greatly enhanced her strength in the upper right.