Rulebook Problems

All Things Chess
1

No, this thread is not about problems with the 5th (or any other) edition of the USCF rulebook.

Rather, it is about chess problems (puzzles), like white to move and win, but with a twist. Retrograde analysis is required, along with a strict, almost maniacal, adherence to the rules of play.

In order to give everybody a chance, please don’t post spoilers (solutions):

  • for problem 1, until about 7 pm EDT on Monday, March 28, 2011.
  • for problem 2, until about 7 pm EDT on Tuesday, March 29, 2011.
  • for problem 3, until about 7 pm EDT on Wednesday, March 30, 2011.

Until then, please limit your posts to snide remarks (but keep it gentle), general questions (if it doesn’t give too much away), and expressions of bewilderment.

Problem 1: In the following position, which player made the last move, and how do you know? Describe this move as fully as possible, given the conditions of the problem.

Hint: Interpret USCF rule 14D very literally.

Problem 2: Here black made the last move. What was that move? Describe the move as fully as possible.

(Same hint as for problem 1.)

Problem 3: Here white made the last move. What was that move? Describe the move as fully as possible.

(Same hint as for problems 1 and 2.)

Think now, post later!

Bill Smythe

2

Didn’t those come out of a book of retrograde analysis chess problems? If I remember correctly, there were 50 of those problems in the book.

I think its was Sherlock Holmes Chess Mysteries.

http://www.amazon.com/Chess-Mysteries-Sherlock-Holmes-Tantalizing/dp/0812923898#_

Edit: The reason I ask is because all three of those problems look really familiar. Although I never looked up the answers. (Retrograde chess problems just isn’t on my radar.)

I know there is a small sub culture of people that like retrograde chess problems, but few books on the subject. Although I’m sure there are a lot of published problems scattered in history in various publications. It wouldn’t surprise me if some even dated pre 1900.

3

I have the problem cover of Arabian Knights on my website. It’s also just under Page 7 in Google Images. The whole cover is a line or two under Page 5.

4

I invented those three problems, all within the last few days. I do hope they haven’t been invented before, although that’s always a possibility.

I have that Holmes book, and looked through all its diagrams just now. I didn’t find any matches.

I doubt Holmes would have made any use of rule 14D. That rule discusses “dead positions” (FIDE terminology) or “insufficient material to continue” (USCF terminology). By definition, such a position has occurred if there is no sequence of legal moves leading to either player being checkmated.

Stripped to its essentials, 14D (especially 14D4) says that, as soon as a dead position is reached, the game is immediately over (drawn).

The following, for example, is a dead position. Black never gets to play …Kxg5, because the game is already over.

That’s what I mean by a very literal (almost maniacally so) adherence to 14D. Adhere thusly, and thou shalt solve.

Bill Smythe

5

As long as we are talking about non-checkmate, non-stalemate, dead positions, how many pieces and pawns can be on the board and the position still dead? Below is a position with 22 pieces&pawns that requires five pawn captures by black and four by white.

and this one has 23 pieces&pawns and requires a total of one pawn capture and one promotion.

I can think of a way to get to 26 pieces&pawns (albeit it would be stalemate the following half-move). Can anybody get up to 27?

6

By “capture” I assume you mean “pawn capture” (i.e. a capture by a pawn). Otherwise, number of captures plus number of remaining pieces would always have to add up to 32.

Undoubtedly you tried to come up with a dead position with 32 pieces – probably impossible.

There is a well-known 12-move stalemate with all pieces on the board – it’s in Hartston’s How to Cheat at Chess – but if it were the opponent’s move, it would not be a dead position, let alone stalemate. I once tried to come up with a 32-piece position where both players are stalemated (i.e. the position is a stalemate no matter whose move it is), but of course no luck.

I think it’s also possible to have 32 white pieces and only the black king, where white is stalemated. But I’ll put this post to bed for now.

Bill Smythe

7

It looks like I put my edit in before your response. That way it looks like you simply mis-read my (apparently) never-edited post.

P.S. There may be a bughouse position where one board has just two kings, the other board has 31 black and 31 white pieces, and the position is dead. I kind of doubt it though.

8

I don’t know about 32, but you can do 16 with no promotions.

9

Oops.

Can you do 16 without pawn captures? :slight_smile:

Bill Smythe

10

Avoiding both pawn captures and promotions does not look feasible.

11

Come to think of it, if the white pawns are placed on the black side of the board (and vice versa) then I wouldn’t have to worry about pawn captures because they are all placed beyond the point of capture.

So this is one of the two boards with a totally dead bughouse position.

12

Hey – where are all the spoilers? The starting time has now passed – at least for 2 of the 3 problems.

Problem 1: In the following position, which player made the last move, and how do you know?

Remember, you are to interpret USCF rule 14D very literally.

In all three of these problems, the position shown is a dead position – a position where no checkmate (of either player) is possible, even if the players cooperate in trying to find a checkmating sequence.

Under rule 14D, as soon as a dead position arises, the game is immediately over, and is drawn. Therefore, the position which arose immediately prior to the diagrammed position must not have been a dead position, else the game would have been over already, and the diagrammed position would not have had an opportunity to arise.

The trick, then, is to find a non-dead position which leads, in one half move, to the diagrammed position.

Examples of dead positions are (1) K vs K, (2) K+N vs K, and (3) K+B vs K. However, much more complicated positions can be dead, too.

OK, everybody, lead the cheer:

"What do we do? Solve! When do we do it? Now!"
"What do we do? Solve! When do we do it? Now!"
"What do we do? Solve! When do we do it? Now!"

etc.

Bill Smythe

13

Ah, now I get it.

14

In problem 1, White moved last, KxR or KxP

In problem 2, Black played KxN

15

Why not KxQ?

Wasn’t the position already dead? How could Black have lost?

16

I guess I shouldn’t try to solve chess problems before my first cup of coffee.

For problem one, as long as the King isn’t on a6, the captured piece can be a Queen.

17

Instead of … KxN, black could have played BxB with the following being one of the potential mates:
… BxB
Na6 Bg1
Nb4 Kb8
Na6+ Ka8
Kc7 Bb6+
Kc8 Ba7
Nc7#
The Nb4 through Ka8 moves would be unnecesary if the K started on a8 instead of c8.

18

Oh, right, I didn’t think of that.

19

For problem three, KxN appears to be the only answer. The Knight got to b1 from one of three places, either a check on a3 or c3, or via a promotion on b1 from a pawn capturing White’s Knight.

20

Bill asked for as complete a move as necessary. Which square did the K come from, and why.