Life In 19x19

I really think overplay is a bad way to describe it... Not only is it the wrong term, but also confers a weird connotation. Starting a ko is often the best move - to call it overplay makes no sense to me.

illluck wrote:I really think overplay is a bad way to describe it... Not only is it the wrong term, but also confers a weird connotation. Starting a ko is often the best move - to call it overplay makes no sense to me.

Exactly. Sometimes the best result from an invasion is a life&death ko.
If a ko is good or bad depends on the rest of the board, it's not always easy to figure it out.

illluck wrote:I really think overplay is a bad way to describe it...

I agree. But it is the best that I could do on the spur of the moment. I'm trying to convey the idea that the person who creates the ko is reaching for something that he could not otherwise achieve.

Try this thought experiment: suppose that you have double ko on the board - which, as you probably recall - can be a source of endless ko threats for one player. Furthermore, suppose that the ko is huge, and that it is to your advantage, such that you have an endless source of game-winning ko threats. In such a situation, any attempt by your opponent to create another ko elsewhere on the board is an overplay. Any attempt by you to create another ko is not.

Those are the extreme ends of the spectrum. Most kos lie somewhere between.

Joaz Banbeck wrote:In such a situation, any attempt by your opponent to create another ko elsewhere on the board is an overplay.

I'm not sure if this is strictly true. He has the double ko to use for ko threats; you create a ko, he activates the double ko and then takes the ko. At this point trying to play ko threats to win the ko is pointless, but eventually he will have to forgo a move elsewhere on the board to win the ko; otherwise eventually you'll find a way to make a third ko, and he'll have to give up one of them.

And if it's an approach ko you can fill in the double ko. And of course if the ko is really huge, you're allowed to ignore the double ko.

I think the thought experiment you want is "imagine finding this local situation on the board when the ambient temperature on the board is zero, and all the ko threats have been filled in." Unlike any other situation in the game, a line of play that would be improper under that circumstance can be excellent under any other circumstance - even when all the moves left are 1pt gote.

I agree to say ko must involve overplay is wrong. Kos and overplay are orthogonal. Ko is a shape that can happen in a game of Go: it's like saying hane is overplay or one-point jump is overplay. It's nonsense. Sometimes those moves might be an overplay, sometimes they might be slack, sometimes they might be bad, sometimes they might be good, sometimes they might be awful, sometimes they might be brilliant.

What you could certainly say is ko is complicated, and therefore is particularly suited when a strong player wants to get a better position than he deserves against a weaker player. That doesn't even mean he has to overplay, often you can just sit there and play good moves whilst your opponent goes and makes bad ko threats. Of often the weaker player will be a chicken and avoid playing a ko when to do so is the best move.