Mutual zugzwang

[Timothy Chow]

This is an off-topic post because it's about chess, but I know that
Paul at least is interested in chess.

In Round 5 of the ongoing Tata Steel chess tournament, there was a
stunning upset, when the reigning women's world champion, Ju Wenjun,
defeated Alireza Firouzja, one of the world's best players. From a
chess theorist's point of view, one of the most fascinating positions
that arose was the endgame position below.

| | | | | | | | |
| | |p|k| | | | |
| | | | | | |p| |
| | |P| | | | |p|
| | | |P|R| | |P|
| | | |r| | |P| |
| | | | | |K| | |
| | | | | | | | |

https://www.janko.at/Retros/d.php?ff=8/2pk4/6p1/2P4p/3PR2P/3r2P1/5K2/8

This position is an example of what is known as a "mutual zugzwang":
neither player wants to be the one whose turn it is to play. Black to
play loses, but White to play only draws. Endgame specialists have long
known that mutual zugzwang positions are extremely subtle, and John Nunn
would systematically dig them out of endgame tablebases and explore
their ramifications, but they rarely arise in practical play.

In real life, Ju was White, but in the position above, it was Black to
move, and so White was winning. However, if the Black pawn on g6 had
been on g7 instead, then Black could have played g7-g6 and drawn.

Robert Hess and Jovanka Houska were commentating live, and it's quite
something to watch their jaws drop in amazement as they gradually work
out (with engine assistance, of course) the subtle difference between
the Black pawn being on g7 versus g6.

Their analysis is briefly interrupted by the conclusion of a different
game in the tournament, but you should continue listening, because they
come back to the Ju/Firouzja game afterward.

---
Tim Chow

[Stick Rice]

Post by Timothy Chow
This is an off-topic post because it's about chess, but I know that
Paul at least is interested in chess.
In Round 5 of the ongoing Tata Steel chess tournament, there was a
stunning upset, when the reigning women's world champion, Ju Wenjun,
defeated Alireza Firouzja, one of the world's best players. From a
chess theorist's point of view, one of the most fascinating positions
that arose was the endgame position below.
| | | | | | | | |
| | |p|k| | | | |
| | | | | | |p| |
| | |P| | | | |p|
| | | |P|R| | |P|
| | | |r| | |P| |
| | | | | |K| | |
| | | | | | | | |
https://www.janko.at/Retros/d.php?ff=8/2pk4/6p1/2P4p/3PR2P/3r2P1/5K2/8
neither player wants to be the one whose turn it is to play. Black to
play loses, but White to play only draws. Endgame specialists have long
known that mutual zugzwang positions are extremely subtle, and John Nunn
would systematically dig them out of endgame tablebases and explore
their ramifications, but they rarely arise in practical play.
In real life, Ju was White, but in the position above, it was Black to
move, and so White was winning. However, if the Black pawn on g6 had
been on g7 instead, then Black could have played g7-g6 and drawn.
Robert Hess and Jovanka Houska were commentating live, and it's quite
something to watch their jaws drop in amazement as they gradually work
out (with engine assistance, of course) the subtle difference between
the Black pawn being on g7 versus g6.
http://youtu.be/ZKPZX6gGRug
Their analysis is briefly interrupted by the conclusion of a different
game in the tournament, but you should continue listening, because they
come back to the Ju/Firouzja game afterward.
---
Tim Chow

Anyone who watches chess online knows of it anyway but just in case we'll put it out there. GothamChess is the most popular by far chess channel for coverage. It's run by Levy Rozman who basically retired from competitive chess around Covid and when he realized he could bank covering chess. His highest level achieved was a solid IM which makes him good enough to cover the greats and his commentary and click bait is world renowned.

While it is quite the upset as there's over a 200 point difference in their ratings, it happens. Here's his video on this particular game.

Stick

[Timothy Chow]

Post by Stick Rice
Anyone who watches chess online knows of it anyway but just in case we'll put it out there. GothamChess is the most popular by far chess channel for coverage. It's run by Levy Rozman who basically retired from competitive chess around Covid and when he realized he could bank covering chess. His highest level achieved was a solid IM which makes him good enough to cover the greats and his commentary and click bait is world renowned.
While it is quite the upset as there's over a 200 point difference in their ratings, it happens. Here's his video on this particular game.
http://youtu.be/FddVeNDNoTQ

I find GothamChess entertaining sometimes, but his analysis is not
always on the mark. For example, at 8:30 he says that Re5 forces
...g6 and wins, but this is probably not correct. If Black plays
...Kc6 instead, White retains an advantage according to Stockfish
but the win is by no means clear.

Again, for those who want to understand this position, I recommend
Houska and Hess's analysis.

---
Tim Chow

[[e-mail]]

Post by Timothy Chow
This is an off-topic post because it's about chess, but I know that
Paul at least is interested in chess.
In Round 5 of the ongoing Tata Steel chess tournament, there was a
stunning upset, when the reigning women's world champion, Ju Wenjun,
defeated Alireza Firouzja, one of the world's best players. From a
chess theorist's point of view, one of the most fascinating positions
that arose was the endgame position below.
| | | | | | | | |
| | |p|k| | | | |
| | | | | | |p| |
| | |P| | | | |p|
| | | |P|R| | |P|
| | | |r| | |P| |
| | | | | |K| | |
| | | | | | | | |
https://www.janko.at/Retros/d.php?ff=8/2pk4/6p1/2P4p/3PR2P/3r2P1/5K2/8
neither player wants to be the one whose turn it is to play. Black to
play loses, but White to play only draws. Endgame specialists have long
known that mutual zugzwang positions are extremely subtle, and John Nunn
would systematically dig them out of endgame tablebases and explore
their ramifications, but they rarely arise in practical play.
In real life, Ju was White, but in the position above, it was Black to
move, and so White was winning. However, if the Black pawn on g6 had
been on g7 instead, then Black could have played g7-g6 and drawn.
Robert Hess and Jovanka Houska were commentating live, and it's quite
something to watch their jaws drop in amazement as they gradually work
out (with engine assistance, of course) the subtle difference between
the Black pawn being on g7 versus g6.
http://youtu.be/ZKPZX6gGRug
Their analysis is briefly interrupted by the conclusion of a different
game in the tournament, but you should continue listening, because they
come back to the Ju/Firouzja game afterward.
---
Tim Chow

Many thanks for this. I did not know about this.
I am indeed interested in chess.
I performed well in a recent category 2 chess problem solving competition.
The details are here: https://www.schakeninhoogland.nl/2023/12/29/grandioos-knoth/

I think the correlation between chess and backgammon is quite high.

Paul