Talk:Fortress (chess)

We may want to add Smirin-Hiarcs 8, where Smirin's 48.Bb4! offered Black the choice of an opposite-colored bishop ending or a bishop v. knight ending where Smirin had an impenetrable fortress. Krakatoa 01:26, 12 October 2006 (UTC)

I think so too. I think it is a better, or at least more typical example from an actual game than the one in there currently from an actual game. Bubba73 (talk), 02:15, 12 October 2006 (UTC)

Should defense perimeter be merged into this article?

I have tagged defense perimeter for a possible merge into this article. A Google search -- chess "defense perimeter" -- seems to bring up relevant hits only from (a) the Wikipedia article itself and (b) references to Soltis' book "The Art of Defense in Chess." [1] The term seems to be Soltis' coinage, one not used by other chess writers. Although Soltis' book was published over 20 years ago -- Amazon shows that the paperback was published Sept. '86 [2] and I know the hardcover came out before that -- other writers outside of Wikipedia don't seem to have followed Soltis' lead. I am a chess master, pretty well-read, and was unfamiliar with the term before I saw it in Wikipedia (even though I read the hardcover of Soltis' book cover-to-cover around 25 years ago). "Defense perimeter" is at a minimum very similar to "fortress," and is a short article -- it was one paragraph, with one reference, before I decided that a problem I'd put into fortress (chess) should be moved into defense perimeter if the definition in the latter article was correct. In short, I suggest merging "defense perimeter" into "fortress chess," with a redirect at the former and a mention of Soltis' terminology in the latter. Thoughts? Krakatoa 20:00, 15 October 2006 (UTC)

I agree with you. Defensive perimeter is a special case of a fortress, so I favor making defensive perimeter a section under Fortress. Bubba73 (talk), 00:42, 16 October 2006 (UTC)

I also agree. I haven't seen the term "defense perimeter" either. Seems like nobody else followed Soltis' lead. youngvalter 15:01, 16 October 2006 (UTC)

Everyone who's responded has agreed on a merge, and no one has spoken against it, so I've gone ahead and merged the d.p. article into the fortress article. I hope no one has a problem with that. Krakatoa 04:06, 19 October 2006 (UTC)

The diagram is inaccurate?

To my limited chess knowledge, it seems like the diagram on the right of the page is incorrect. The accompanying text states that the black king can shuffle between a8 and b7 "indefinitely". Wrong, if it's white's turn, play and win: kb4, kb7; ka5, ka8; ka6, 1-0. This can be avoided by black by moving to column c, but this results in a shiny new queen for white and black will likely still lose. Am I missing something? 69.136.195.152 (talk) 01:49, 24 November 2007 (UTC)

You are missing the fact that after 3. Ka6 the position is a draw becasue of stalemate. Bubba73 (talk), 01:53, 24 November 2007 (UTC)

The first paragraph of that section states that the black king can shuffle between two squares, and White can do no better than stalemate. Bubba73 (talk), 04:05, 24 November 2007 (UTC)

Marcotulli vs. Malström, 2001

Note that this section should read "3. ...Ka3 and White punches Black for trying to cheat". In the diagrammed position the Black King cannot reach a3 in one move, and does not move on moves 1 or 2. :) Captain Pedant (talk) 08:22, 27 April 2012 (UTC)

Whitaker vs Ferriz

One optimal line would be 50...Qc7+! 51.Kh3 h4 52.Rd3 Kg5 53.Rd5+ Kg6 54.Rd3 Qe5 55.Ra3 Qe6 56.g4 Qe2 57.Rb3 Kg5 58.Ra3 Qf1+ 59.Kh2 Qc4 60.Kg2 Qc6+ 61.Kf2 Qc5+ 62.Kf3 Qxa3+ 63.Ke4 Qb3 64.Kd4 h3 65.Ke4 h2 66.Ke5 h1=Q 67.Kd6 Qhb7+ 68.Kc5 Q3b4#. Double sharp (talk) 16:40, 20 February 2016 (UTC)

Different kinds of fortresses

I think the article might be improved by carefully explaining what different kinds of fortresses are possible and what makes them possible. The current article loosely categorizes fortresses by material on the board, but touches on the distinction I'd like to see expanded upon in the Positional draw section. For example, many of the example fortresses can only exist due to stalemate being a draw. But the example where all 16 pawns form an interlocking wall with black up by two rooks and a wrong-colored bishop relies not on stalemate, but on perfectly separating the board into two areas with no pieces able to move from one to the other. The position with two rooks vs one bishop, where the bishop has one rook pinned and also attacks that rook with its king is a fortress for yet another reason. MarSch (talk) 09:24, 25 February 2016 (UTC)

In the end they all boil down to the "dead position" rule: a position is dead if no sequence of legal moves from it can lead to either side being checkmated. A blocked position is certainly a case of this, but stalemate is certainly the degenerate case: no sequence of legal moves from a stalemated position can result in checkmate because there are no sequences of legal moves from a stalemated position. Double sharp (talk) 10:41, 15 August 2017 (UTC)

But the pawn blockade with black up two rooks position is not a situation where no legal moves could lead to checkmate. If white makes a mistake and captures one of the rooks, the position opens up. 74.102.165.249 (talk) 03:03, 25 August 2017 (UTC)

You are right, it is not a dead position: if you removed the rooks, it would be another story. But there are some similarities, though my analogy is in hindsight not good (sorry). Similarly to how perpetual check draws because with best play the stronger side can make no progress without causing stalemate, creating a defense perimeter results in the stronger side being unable to make any progress if the weaker side chooses not to release the position. Double sharp (talk) 07:21, 29 December 2019 (UTC)

An excellent positional draw example (in the opening!)

Bilek. vs Schussler, 1978.

Bilek vs. Schussler, 1978

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

White to play

Bilek vs. Schussler, 1978

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Position after 12...Nd5, draw!

Here the "brilliant" 10.Nf6+ gxf6 11.Bxf7+ Kxf7 12.Qxd8 was played, "winning the queen" – which ran into 12...Nd5, whereupon a draw was immediately agreed. White's golden extra queen is trapped, and with 13...Bb4+ threatened, there is nothing better than 13.0-0 Bg7 14.Qd6 Bf8 15.Qd8 Bg7 with a draw by repetition. Double sharp (talk) 07:28, 29 December 2019 (UTC)