Full disclosure - this is a rule that may confuse you at first. Fortunately, it is not as complicated as it may first appear. I for one (although many would disagree) think that a good ko fight is one of the most fun things you can have in a Go game.
Go games can be really long. However, they must never be endless. To prevent the possibility of an endless game we have a rule called “Ko”.
Just imagine a situation like this one. Given enough stubbornness, those players would be playing until they pass out. (feel free to watch for a while)
To prevent health problems connected with exhaustion, we have this rule:
Can you ever capture that stone then? What are your options? Basically, you have two:
⬤ You deem the stone not important for now and play elsewhere, letting your opponent end the ko by connecting her endangered stone if he or she wants to.
⬤ You deem the stone important enough to fight the ko. You still have to play elsewhere (of course) but you try to find a move your opponent will feel compelled to respond to immediately instead of resolving the original ko (we call that a ko-threat). After that, you retake the ko stone and the fight is on!
Confusing? Then check out the following examples. It will be clear in no time.
Black to play
And on 19x19 board, there are usually much more than only one threat, so the ko fight can span over several moves. The hard part - of course - is judging if any given threat is big enough to respond to or whether it is more beneficial to end the ko. But hey, I said the rules are easy, not the game itself.Let me get back to this one later