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If you enjoyed this, you might like Mind Chess, which can be played without a board and pieces [1]:

Consider Mind Chess. Two players face each other. One says "Check." The other says "Check." The first says "Check." This continues until one of them says, instead, "Checkmate." That player wins -- superficially. In fact, the challenge is to put off checkmate for as long as possible, while still winning. This may be better stated: you truly win Mind Chess if you call "Checkmate" just before your opponent was about to.

[1] http://www.eblong.com/zarf/essays/mindgame.html

Mentioned in TFA: This version of chess is given by Martin Gardner in his "Mathematical Games" column of July 1980 (pages 27 and 31) — https://www.jstor.org/stable/24966361 — and the analysis of White's mate is given in the column of August 1980 (page 18) — https://www.jstor.org/stable/24966383.

I do wonder how things would change if the board were 9 cells long; 10 cells long; etc. Also, it seems "in the spirit" to permit castling if neither K nor R has moved yet: i.e., from the position

K _ R N r _ n k

White ought to be permitted to

_ R K N r _ n k

(Or maybe there's a stronger argument for R K _ N r _ n k, actually. The former was conceptually "rook moves halfway toward king, then king moves to the other side of rook"; but the latter is "rook moves two steps in king's direction while king moves to the other side of rook.")

I'm pretty sure this wouldn't change the analysis on the 8-cell board at all, though. I wonder if it would change the analysis on any size of board.

1D Go is also interesting and doesn't require any change in rules or starting position. TIL that it is known as Alak [1]. One of the open problems in our Combinatorics of Go paper [2] is whether you can play a game that goes through all possible legal 1xn positions for any n>2, which we were only able to verify up to n=7.

[1] https://senseis.xmp.net/?Alak

[2] https://tromp.github.io/go/gostate.pdf

Those who play go may enjoy the variants: https://www.govariants.com/variants/rules-list Tetris is a fun one to try!

I love chess! This version was fun too.

If 1. Rx6,it is stalemate. So it must be 1. N4 N5. Then we could proceed with, 2. Nx6+ K7. Now, if you capture the knight (Rxe), it is stalemate again. So sacrifice the knight, 3. R4 Kx6 so that you force black to zugzwang with 4. K2 K7, and finally, 5. Rx5#

This is really nice.

Incidentally, there is an actual 1D game that is one of the most popular games on the planet: Backgammon.

Very cool. Reminds me of 1D Pacman: https://abagames.itch.io/paku-paku

Reminds me of Edwin A. Abbott's Flatland, where he describes Lineland. A one-dimensional world whose King can only move forward and backward, cannot conceive of sideways, and considers his tiny segment of existence complete and sufficient. The Linelanders are portrayed as pitiable, intellectually imprisoned by their single dimension. Much like us in our three :)

N4 N5 Nx6+ K7 R4 Kx6 R2 K7 Rx5#

That finally confirmed that I am too regarded for chess if even 1D is too hard yay

If you like 1D chess, you'll probably like other chess-themed puzzles as well: https://chedoku.com/blog/chessPuzzles

I went in other direction ;-) https://topce.github.io/chess960x32/

Haha, i was taking N4 and N6, but didn’t figure the steps after that.

To win we need to let knight die because rook can move multiple steps to kill the king.

From a third person perspective R2 is a deceptive move that takes advantage algorithm to make the black king back off to kill its knight.

I honestly thought this post was going to be about the Iran war.

I was confused why 3.R2 is drawing, but not 3.R4 since black can check with the knight either way, but it's fairly obvious in hindsight - if black checks instead of capturing, you don't take, you go K2 and force black into zugzwang. Clever.

It took me an embarrassing number of attempts to win.

It was a lot more fun than I first thought!

I don’t know why this is stalemate: N4 N5, N6 K7, R5. Wouldn’t rook have the king in checkmate?

Don't know when was the last time I had so much fun with chess. Quite intuitive, clicked on the first click.

Would enjoy so much if there were more of these, feels like an obligation-free chess puzzle.

I was only able to beat this after a couple retries. The hint was hard to read.

I won after four attempts. Pretty sure it was perfect play so yes white has forced win

Zugzwang!

Nice, fun and interesting! :)

Finally, a version of Chess I can understand. Thank you.

Oh very interesting. Even with these restrictions, there are quite a few variations, and it seems only one ends up with white winning.

I was expecting a blog post regarding Iran strategy...

That's actually a fun little puzzle.

Hello

It's very interesting and fun!)

Cool idea. This is smart and lean. I like it

Silly nice brain teaser

Nice! :)

Fun stuff, love it!

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love it!

i could not beat it, and i can't read that chess notation

The first move is always: white rook takes black rook, then the only remaining move for black is to move the knight away, which results in checkmate.