Kikashi first!

White 1 threatens Black's framework link. How should Black respond?

Safe!

Black 2 connects but white 3 cuts off one black stone. At the end of the game Black is one point behind. But Black could do better! - see next diagram below.

Kikashi!

Black 2 is perfectly safe. White 3 is forced thus allowing black 4 to complete the framework connection. This time black wins by three points. By comparing this result with the previous diagram we can see that the value of this advantageous preliminary forcing move, or kikashi, is four points. If you are still not sure about the safety of black 2 see the next diagram below.

Why White cannot resist.

White 3 is overly optimistic. Black 4 isolates the white stones. Due to lack of eye space, the only chance that White has of rescuing these stones is by killing the lower black stones. These black stones are also isolated but have more liberties. White 5 forces black 6 and gains some liberties before coming back with white 7 to prevent immediate capture. After black 10 the situation becomes clearer. Neither set of stones can now gain more liberties. The black group has four more liberties than the white. It is White's turn so one black liberty can be removed, but in the race to capture, Black has three moves to spare.