what's the value of a king?

it can be worth 1000000000000000000000000000000000000000000000000000000000000000000 and also it can be worth 0.0 . You get no points when you checkmate but you get everything when you do it. and basically if it wasn't a king its worth 3 points...

Yeah, but the game is finished when that happens, so it doesn't get to count.

About 3.5 points.

It's pretty well known that a king has a fighting value between a minor piece and a rook.

This is perhaps most noticeable in endgames when dealing with opponent's pawns. It's typical to have a knight or bishop relieve the king of blockading duty, and it's typical to have a king relieve a rook of blockading duty.

But also offensively... having a king infiltrate and attack weak pawns is generally better than a knight or bishop, and not as good as a rook.

A pawn can be captured in 1 move, and can capture any piece in 1 move.

A queen can be captured in 1 move, and can capture any piece in 1 move.

Therefore pawns and queens are worth the same.

Or maybe we shouldn't base value on captures

#25
"a king has a fighting value between a minor piece and a rook"
++ I doubt this and would say a fighting value like a minor piece
A king works at close range, a knight at intermediate range, and a bishop at long range.

"a king infiltrate and attack weak pawns is generally better than a knight or bishop"
++ That is right, that is close combat. For forking 2 pawns the knight is better. For holding off pawns on 2 wings the bishop is better.

Various players over the years have assigned a value of 4

In the table I link below it seem seems Yevgeny Gik agrees with your reasoning and conclusion. In the comment column it says Soltis points out problems with this... I have no idea what his issues are.

https://en.wikipedia.org/wiki/Chess_piece_relative_value

In any case I independently arrived at ~4 after studying endgames and realizing what I mentioned in my first post here. Interestingly Fischer is listed in that wiki as valuing the king as infinity... which I think is incredibly stupid, so what do I know

In the endgame a king is usually stronger than any minor piece, and can often overpower a rook. Having the more active king is often a winning advantage in the endgame,

It says, "The king's value represents its importance, not its strength."

The source cited is Bobby Fischer Teaches Chess, Bantam Books, 1972.

That's not stupid at all. He's right.

In fairy chess, the mann, which is the non-royal king, is often given the value of 1.5.  Better than a pawn, but mobility problems make it worth not much more than a pawn. And the mann doesn't have the restrictions of a king.

IMHO, I always look at the king this way.  It is a terrible attacking piece, who is only the most valuable piece when every other piece has been taken.  

When GMs rate it a 4, I often think it isn't because it is actually worth a 4, but rather that beginners should always look at king candidate moves at the endgame, since it is most at risk and also the most overlooked to be an attacker.

I agree

Oh... now that I read your post... this was from Bobby Fischer Teaches Chess?

Well that's ok then, because Fischer didn't write that book. Also the book is (primarily) a collection of beginner level mate puzzles (mate in 1 and 2). So over emphasizing the importance of the king serves a useful function in a book like that.

Anyway, the strength of pieces are based on mobility. A higher mobility can be thought of as a higher probability that a piece will be useful in the future.

I got this,..