Zugzwang

[perseus]

Any good (i.e. classic , interesting) zugzwang positions on Stan's?

I do not seem to have these positions, although when I played a very long time ago, I remember them coming up reasonably frequently.

[Diet_Coke is better than chess]

In pawn endgames sometimes the difference between a win and a draw (or even a loss) can be who's move it is.

[ZorMaster]

Isn't that a term used in combinatorial game theory?

Zugzwang means that one player is put at a disadvantage because he or she has to make a move — the player would like to pass and make no move, but the fact that the player must make a move means being forced into a significantly weaker position. In combinatorial game theory, it means that it directly changes outcome of the game from a win to a loss. The term is used less precisely in other games.

Find it in one my chess encyclopedea.

[perseus]

I was thinking mostly of the combinational zugzwang in complicated middle game strategic/tactical positions that I usually use the term.

However, it may also be correct to use it for "Queening a Pawn" positions (or failing to do so in the example). I think the opposition outwitted me and got a draw in this game (I think I saw it coming, but I could not seem to do anything about it):

www.stansco.com/cgi-bin/nc_game.cgi?352756?52b?black?large

Did white do it on purpose? He had plenty of chances for a draw earlier.

There may be a way for Black to win, but I could not work it out!

[ZorMaster]

I shall make a depth analizing for you.

Dou you want that i publiced it here or do i have to send it to you?

[perseus]

zormaster said:

I shall make a depth analizing for you.

Dou you want that i publiced it here or do i have to send it to you?

Yes, please. Publish it on here please, so anyone can benefit from your work. I understand computer programs can do this sort of thing as well.

I got as far as chasing the Rook around to swap off and then I still could not get the pawn home?! (or is it !?)

When it came down to it, my chess brain was not up to it.

I thought of getting my Rook on to the queening square file in front of it instead of behind it so I could get his King out of the way, but I could not see me achieving that this side of Christmas.

Most likely, I would have to read a book on pawn endings. Most likely, I would not have the time.

[ZorMaster]

perseus said:

zormaster said:

I shall make a depth analizing for you.

Dou you want that i publiced it here or do i have to send it to you?

Yes, please. Publish it on here please, so anyone can benefit from your work. I understand computer programs can do this sort of thing as well.

I got as far as chasing the Rook around to swap off and then I still could not get the pawn home?! (or is it !?)

When it came down to it, my chess brain was not up to it.

Gonna be own hand and brainwork without computer assitence.

[perseus]

I had another look. It looks impossible to me.

If I get the Rook up to in front of my pawn, I cannot get my King up to support it because he can block it off with a Rook on a horizontal file.

[savin]

Perseus,

I took a quick look at the game. It is definately a draw at the end of the game -- although I don't know why white did not just play Rxf7 on move 54 and really make it a draw?? But anyway, its still a draw.

Going backwards through the moves the game is a draw until I look at black's move 45 ... Rb8

This move lost you a tempo. In fact white should have replied Rb7 which kind of forces Ra8 followed by Ra7 etc. You can't take the white rook because the pawn will queen.

But .... lets say you had not wasted the tempo. and played instead
45 ... Kg7

This might have won the game.

Analysis. The white rook really can't move. That means the King must come over to help. But your connected pawns become quite strong. White really has three options for move 46:

46. Kc4 (go to help)
or
46. a6

However. 46. a6 is followed by Ra5 .. and its not nice.

46. Ke3 may be the only move ..get back in front of the connected pawns. I think Kc4 or a6 eventually lose??

now:
46. ... g5 stops the king getting to f4.. so does Rb4 but its a wasted tempo.
47. Kf3 and its looking drawish again....

Bascially we don't want bthe King in front of the pawns.

Going back further the next thing I see is black's 43. ... h4
This move really didn't do much. Perhaps we could get an advantage by getting the King to e7. So lets try 43. ... Kf8
hmm... if we are going to try this then 42. ... h4 was not worth making either. so lets look at other moves on 42.
perhaps 42. ... Kf6 ? to get our King forward.
this might work .. but its not clear..

going back further...

AH!!!!!!
39. ... Rb5 is a completely wasted move. A full tempo loss. Now we have something.

From an end game strategy point of view you should have played:
39: ... Rh1 (but maybe g5 would be ok as well? .... hmm maybe Rh1 is a wasted 1/2 tempo..... we need to be ab;le to stop the white pawn on a5. but we can play g5 in safety. So lets try 39. ... g5

now..
there are two lines for white Ke4 to get the King over or a6 to get the pawn further advanced. a6 looks like a black win. I will come back to why..lets see what happens with Ke4.. but it looks like a black win as well.

40. Ke4 Rh1 (may be a better move I will stick to a text book play)
41. Kf5 the king would like to go to f4 but it can't. f3 is a tempo loss. a6 still loses.
41. ... h6 protects the pawn and keeps us advancing.
If you compare the position to the one at the end of theb game you will see a biug difference. Blacks pawns are advanced, the rook is on h1 and the white pawn is still at e3 and not doing much. The rook moves for white all result in Rf1+ and the king must retreat to e4. The other possibility is Kg4?? This move looks weak after Rg1 check Kf3 to protect the e3 pawn. SO lets see what happens with Rd7
42. Rd7 Ra1 (I think it gets a half tempo)
43. Rd5 Rf1+
44. Kg4 (or ke4?)
This was the point of everything. We now play
44. ... Kg3 if the rook checks we play f3 and we have moved all of our pawns and black has gained nothing.
45. Rd6+ f6
46. Kg3 (if black plays a6 we still play h5+ so it makes no difference)
46. ... h5
47. a6 rg1+
48. Kf3 Ra1 (to stop the pawn)
now it does not matter what white does... the problem is blacks move of Ra4.
49. Rb6 Ra4
50. e4 (blocks the rook)
50. ... Ra3+
now Kg4 is a mate so the King must move back.
51. Kf2 g4
52. e5 (whites last hope to counte attack)
52. ... h3 its too late
53. Rxf6+ Kg5
unstoppable now.

So what about the a6 move on 40?
40. a6 g4
41. Rc7 Ra5
42. a7 h5
now if the rook leaves the 7th rank the pawn gets taken. So the only option is to get the King to nthe pawns or perhaps e4? but its too slow.
43. Ke4 Ra4+
44. Kf5 g3
45. e4 (only real chance)
45. ... g2 and I think you can see the problem now for white.

I hope this makes sense. Tricky end game, easy to miss.

[ZorMaster]

savin said:

Perseus,

I took a quick look at the game. It is definately a draw at the end of the game -- although I don't know why white did not just play Rxf7 on move 54 and really make it a draw?? But anyway, its still a draw.

Going backwards through the moves the game is a draw until I look at black's move 45 ... Rb8

This move lost you a tempo. In fact white should have replied Rb7 which kind of forces Ra8 followed by Ra7 etc. You can't take the white rook because the pawn will queen.

But .... lets say you had not wasted the tempo. and played instead
45 ... Kg7

This might have won the game.

Analysis. The white rook really can't move. That means the King must come over to help. But your connected pawns become quite strong. White really has three options for move 46:

46. Kc4 (go to help)
or
46. a6

However. 46. a6 is followed by Ra5 .. and its not nice.

46. Ke3 may be the only move ..get back in front of the connected pawns. I think Kc4 or a6 eventually lose??

now:
46. ... g5 stops the king getting to f4.. so does Rb4 but its a wasted tempo.
47. Kf3 and its looking drawish again....

Bascially we don't want bthe King in front of the pawns.

Going back further the next thing I see is black's 43. ... h4
This move really didn't do much. Perhaps we could get an advantage by getting the King to e7. So lets try 43. ... Kf8
hmm... if we are going to try this then 42. ... h4 was not worth making either. so lets look at other moves on 42.
perhaps 42. ... Kf6 ? to get our King forward.
this might work .. but its not clear..

going back further...

AH!!!!!!
39. ... Rb5 is a completely wasted move. A full tempo loss. Now we have something.

From an end game strategy point of view you should have played:
39: ... Rh1 (but maybe g5 would be ok as well? .... hmm maybe Rh1 is a wasted 1/2 tempo..... we need to be ab;le to stop the white pawn on a5. but we can play g5 in safety. So lets try 39. ... g5

now..
there are two lines for white Ke4 to get the King over or a6 to get the pawn further advanced. a6 looks like a black win. I will come back to why..lets see what happens with Ke4.. but it looks like a black win as well.

40. Ke4 Rh1 (may be a better move I will stick to a text book play)
41. Kf5 the king would like to go to f4 but it can't. f3 is a tempo loss. a6 still loses.
41. ... h6 protects the pawn and keeps us advancing.
If you compare the position to the one at the end of theb game you will see a biug difference. Blacks pawns are advanced, the rook is on h1 and the white pawn is still at e3 and not doing much. The rook moves for white all result in Rf1+ and the king must retreat to e4. The other possibility is Kg4?? This move looks weak after Rg1 check Kf3 to protect the e3 pawn. SO lets see what happens with Rd7
42. Rd7 Ra1 (I think it gets a half tempo)
43. Rd5 Rf1+
44. Kg4 (or ke4?)
This was the point of everything. We now play
44. ... Kg3 if the rook checks we play f3 and we have moved all of our pawns and black has gained nothing.
45. Rd6+ f6
46. Kg3 (if black plays a6 we still play h5+ so it makes no difference)
46. ... h5
47. a6 rg1+
48. Kf3 Ra1 (to stop the pawn)
now it does not matter what white does... the problem is blacks move of Ra4.
49. Rb6 Ra4
50. e4 (blocks the rook)
50. ... Ra3+
now Kg4 is a mate so the King must move back.
51. Kf2 g4
52. e5 (whites last hope to counte attack)
52. ... h3 its too late
53. Rxf6+ Kg5
unstoppable now.

So what about the a6 move on 40?
40. a6 g4
41. Rc7 Ra5
42. a7 h5
now if the rook leaves the 7th rank the pawn gets taken. So the only option is to get the King to nthe pawns or perhaps e4? but its too slow.
43. Ke4 Ra4+
44. Kf5 g3
45. e4 (only real chance)
45. ... g2 and I think you can see the problem now for white.

I hope this makes sense. Tricky end game, easy to miss.

Savin, thank you. No need for me now to make work of the game

[perseus]

Thanks Savin for the hints. I think your standard is way ahead of mine. And probably my opponent as well. I did not know 54. Rxf7 was a definite draw until it was too late. Learning process. I expect we both suspected when it happened but I did not see it in advance. (I the plan I thought this would win.)

What is the principle here? I thought my connected pawns ought to be stronger but I did not how to do it. (On move 27 I split one of his pawns away.)

39. Rb4 .... a completely wasted move! Hindsight says you are right. I didn't like g5 because it meant splitting up my pawns. So the natural thing (for me) was to move the Rook out of the way so I could go h5.

It was about evens that the opponent would make a boob? I really did not want the opponent play e4. Because that would mean two pawns to worry about.

Then everything went to plan but I simply did not realise I could not win with the extra pawn.

I wne through the moves after g5

44. ... Kg3 if the rook checks we play f3 and we have moved all of our pawns and black has gained nothing. (this is Kg6 which is OK when I wnet through it)

and I am sure that this OK, but white's rook pawn looked dangerous.

g5 looked like the move but was fraught with peril at my standard.

I actually thought the game would be a draw from the start. It is pretty average for Category 2 standard.

[perseus]

PS: I have just played through the g5 move. What I was worried about was the white pawn on a7 with the white Rook behind it on the queening square and nowhere for my King to go to get out of check. I can see now my King could have found a safe place. This may be easy for others to see, but I play for practice OTB and I can't see that far ahead.

[savin]

Perseus,

Its a pretty complicated end game and much of how to play it needs to be known rather than thought through. One of the hardest things to learn is to distinguis between things that look dangerous and things that are dangerous. The white a pawn is only dangerous if the White King gets over there. The black pawn at f6 can be a safety buffer for the black king. So the key is advancing the pawns and trying to keep the black rook in front of them as long as possible. That won't be long. So after that get the black rook to a1 ( or wherever) since it can stop the pawn advancing and still stop the white king from moving.

The other thing to remember is that a nd h pawns are just not as powerful as b and g pawns. The really tricky part about this end game is trying to envisionage where the white king wants to get and how to slow it up. g5 denies f4 and f4 is a place the White King wants to get to.

But as I said ... a very tricky end game

[perseus]

Thanks: a good tip where the White King wants to go.

If I think snooker where the white ball goes, I might remember that!

I think if I had played g5 we might have still be playing at Christmas though.