Molasses ko (Black to play)  

In this position, the local difference between White killing the black stones and Black killing the white stones is 54 points (under Chinese rules). But if Black plays elsewhere and White immediately wants to kill, the game will proceed this way:

• Black tenuki
• White b, takes the ko
• Black tenuki
• White d, captures the black group
• Black tenuki

So White wins the Molasses ko, and captures the black stones, but Black gets three more moves outside than if they had played at a to keep fighting the Molasses ko. If these moves are worth more than 18 points each, Black shouldn't fight the Molasses ko!

In fact, the value of fighting the Molasses ko might be even less, because even if Black keeps fighting, they are not guaranteed to kill the White stones, so the local difference in points between Black tenuki and Black a might be less than 54 points (see the discussion on the status of the Molasses ko). --ArsenLapin?