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Jesper Norgaard
20-07-2009, 10:43 AM
{This example was mentioned in Geurt Gijssen's July column in ChessCafe. It is a Normal game or Rapid game where the start position was wrong, in that White King and White Queen has been reversed, however the two players have not noticed that and both continues as Queen was King and King was Queen.} 1.e4 e5 2.Bc4 d6 3.Kh5 {this is meant to be a threat of 3.Qxf7+ checkmate, but the refutation is even more devastating} 3...g6# {Checkmate!! Why is this possible? In a normal game you can claim an illegal move during the game and have the moves returned to before the illegal move, can't you? Well the problem is that the move 3...g6 checkmate is ending the game immediately, since the only requirement is that the move 3...g6 is a legal move (which it is), not that the start position and all previous moves were legal}

{White sets out a simple trade of pieces} 1.Nxd6+ Nd8?? {the Black move is in fact illegal, as it leaves the Black King in check. Now White could claim illegal move which would certainly lead to that Black should return his Nd8 Knight to c6 and make another legal move - so not really to White's benefit who is a piece down. Can you find a better move?}
Hint: White can checkmate Black instead!

If you think like I do that these examples reveals that there is something wrong in the Laws of Chess that allows gamesmanship and silly games, then please contact your nearest congress man or local chess Politician - this can't be right!

Unfortunately although FIDE accepts these games as legal games with illegal moves, the PGN recorder does not (nor do I) so here are the ending positions for your convenience:

rnbqkbnr/ppp2p1p/3p2p1/4p2K/2B1P3/8/PPPP1PPP/RNB1Q1NR w kq - 0 4

r1bnk2r/pppnqQpp/3N4/4p3/2B1P3/8/PPPP1PPP/R1B1K2R w KQkq - 0 2

Comments, please?

Igor_Goldenberg
20-07-2009, 12:05 PM
Last position is not legal.

Kevin Bonham
20-07-2009, 01:43 PM
Last position is not legal.

I think that's exactly the point. White has delivered checkmate by a legal move in an illegal position and therefore wins the game.

Igor_Goldenberg
20-07-2009, 02:18 PM
I think that's exactly the point. White has delivered checkmate by a legal move in an illegal position and therefore wins the game.

But the final position is illegal, e.g. it cannot be archived by any sequence of legal moves. It cannot be counted as a checkmate.

The first position (with with white king on h5) is legal.

Rincewind
20-07-2009, 02:29 PM
But the final position is illegal, e.g. it cannot be archived by any sequence of legal moves. It cannot be counted as a checkmate.

The first position (with with white king on h5) is legal.

I don't believe the laws state that for a checkmate to be legal it has to be achievable by a sequence of legal moves. The only requirement in this regard is that the move producing the checkmate (i.e. the last move) was legal. The second last move may have been illegal, in this example it probably was illegal as black probably left his king in check.

I've heard the idea of an "illegal position" by other people too. However unless the rules are changed, it is not supported by the laws.

Kevin Bonham
20-07-2009, 02:31 PM
But the final position is illegal, e.g. it cannot be archived by any sequence of legal moves.

Indeed, but again, that seems to be the point. Checkmate with a legal move is checkmate under the FIDE Laws even if the position in which it occurs could not have been reached with any series of legal moves. Therefore, if an opponent plays an illegal move that allows you to mate them in one, and you really want to win the game above all else, you should play Qxf7# right away before they have time to save themselves by noticing that their move was illegal.

I would not play Qxf7# myself in that position. I think it is unsporting to knowingly take advantage of an opposing illegal move in this manner in a normal or rapid game.

Igor_Goldenberg
20-07-2009, 03:05 PM
I just check FIDE laws of chess.

"The objective of each player is to place the opponent’s king ‘under attack’ in such a way that the opponent has no legal move. The player who achieves this goal is said to have ‘checkmated’ the opponent’s king and to have won the game."

"The game is won by the player who has checkmated his opponent’s king. This immediately ends the game, provided that the move producing the checkmate position was a legal move."

There is no explicit definition of "position".

Which means:

It can be argued (to death) that position means placement of pieces on board that be achieved by the series of legal moves (or not).
Then it can argued (also to death) whether move that leads to an illegal position can be legal.
It could also be argued (again to death) whether "checkmate position" must be a legal position.

All in all it means:
1. An arbiter will have to make a decision (in case of dispute) using whatever interpretation (s)he thinks is correct. Not a good idea.
2. Proper wording has to be made by FIDE.
3. Obviously conflicting rules (checkmate ends the game and irregularity clause) have to be reconciled one way or another.

Questions:

1. Suppose white made an illegal move, black responded, white responded, black checkmated. How do you want the law of chess to treat the result?
2. White made an illegal move (leading to a legal position), black checkmated. How do you want the law of chess to treat the result?

Kevin Bonham
20-07-2009, 03:28 PM
It can be argued (to death) that position means placement of pieces on board that be achieved by the series of legal moves (or not).
Then it can argued (also to death) whether move that leads to an illegal position can be legal.

A move that creates an illegal position from a legal one can never be legal.

However, in a position that is already illegal, it is possible to make a legal move while the position remains illegal.


It could also be argued (again to death) whether "checkmate position" must be a legal position.

It is clear that this is not required. Indeed FIDE had an opportunity to declare that all moves must be legal for a checkmate to be valid but decided not to do so. This is discussed on Jesper's recent thread in Arbiter's Corner here (http://chesschat.org/showthread.php?t=10383).


Questions:

1. Suppose white made an illegal move, black responded, white responded, black checkmated. How do you want the law of chess to treat the result?
2. White made an illegal move (leading to a legal position), black checkmated. How do you want the law of chess to treat the result?

I want both of these to be treated as checkmates for the reasons I stated on Jesper's thread - verifying the legality of games after a checkmate is a nuisance for the arbiter and it should be the players' responsibility to ensure their game remains legal and to stop it immediately if an illegal move is played.

Rincewind
20-07-2009, 03:42 PM
It can be argued (to death) that position means placement of pieces on board that be achieved by the series of legal moves (or not).
Then it can argued (also to death) whether move that leads to an illegal position can be legal.
It could also be argued (again to death) whether "checkmate position" must be a legal position.

I'm sure you could argue to you are blue in the face however as far as I am aware, the position terms just refers to the placement of the pieces and does not imply a legal sequence of moves from the starting "position".

I note there is a definition of position (at least with respect to rule 9.2) given which goes...


Positions as in (a) and (b) are considered the same, if the same player has the move, pieces of the same kind and colour occupy the same squares, and the possible moves of all the pieces of both players are the same.

And I think the general convention is exactly this. The term "position" refers the sum of the location of all the pieces and all possible legal moves of the colour with the move.


All in all it means:
1. An arbiter will have to make a decision (in case of dispute) using whatever interpretation (s)he thinks is correct. Not a good idea.
2. Proper wording has to be made by FIDE.
3. Obviously conflicting rules (checkmate ends the game and irregularity clause) have to be reconciled one way or another.

I would argue that an arbiter would just need to be conversant with the laws as they stand and the standard interpretation of them. Not all arbiters are of course.

You can also argue until you are blue in the face about the wording of any set of rules. Adding a clause to define position as the location of the pieces on the board and all possible legal moves for the colour with the move might be nice but as that is already in 9.2 it would seem to be not patently required.


Questions:

1. Suppose white made an illegal move, black responded, white responded, black checkmated. How do you want the law of chess to treat the result?
2. White made an illegal move (leading to a legal position), black checkmated. How do you want the law of chess to treat the result?

How you, I or anyone else would like the laws of chess to treat the result is a little beside the point. The current laws are definite. Legal move ending in checkmate is checkmate and thus ends the game. The problem with looking back 2, 3, 4 or any other number of moves and ensuring all legal moves presents arbiting problems and so while I believe Geurt has wanted to change this law there has been considerable resistance to change.

Jesper Norgaard
20-07-2009, 03:57 PM
I want both of these to be treated as checkmates for the reasons I stated on Jesper's thread - verifying the legality of games after a checkmate is a nuisance for the arbiter and it should be the players' responsibility to ensure their game remains legal and to stop it immediately if an illegal move is played.
The second example is perhaps the best example why I believe this is a serious flaw in the FIDE rule making. If you make an illegal move in a Blitz game, you will (probably) lose the game. Fine, I never liked that rule too much, but at least there are some practical reasons for it. Blitz is Blitz.

But in Rapid and Normal games if you make an illegal move, the worst that can happen after yourself or your opponent discovers the mistake is that you can be forced back to before the illegal move, and a time penalty. Not a big deal. If your opponent tries to play "double jeopardy" and snatch your Queen while you are still in check, it won't work because you simply claim that you started the whole sequence with an illegal move (leaving King in check) and the arbiter must roll back to that position.

However, your opponent can not only inflict material damage to your position, he can outright checkmate you, as in the second example if he is smart enough to take advantage of the rules. It is simply maximum penalty for what otherwise is only severed with a slap on the fingers, the illegal move. Is that really good Laws of Chess? I think not.

Jesper Norgaard
20-07-2009, 04:03 PM
But the final position is illegal, e.g. it cannot be archived by any sequence of legal moves. It cannot be counted as a checkmate.

The first position (with with white king on h5) is legal.

I love how you intuitively suppose without checking any laws that a game of chess should consist of a sequence of legal moves. I feel exactly the same. Although FIDE and Kevin are not ready to be so strict.

Jesper Norgaard
20-07-2009, 04:16 PM
I would not play Qxf7# myself in that position. I think it is unsporting to knowingly take advantage of an opposing illegal move in this manner in a normal or rapid game.
I wish you would. If such a game became public and debated, I think FIDE would change its mind on these matters. In Denmark a famous lawyer knew all the Danish laws and then some (Glistrup) and told his clients that if they put their trust in him, he would arrange with tax dept. that they would have zero (0) tax, by making so heavy deductions in tax that nothing was left for the Danish government. This circus went on for years, with very happy clients. In the end he probably thought he could outsmart God and went on national TV to proclaim that anyone could get 0 tax if they wanted and signed up with him. The result was an earthshaking political victory in the following election, but also he was finally taken to court by the tax department and given prison time, although the courts also hinted at that the laws were not OK.

The Danish tax laws were therefore changed to disallow the tax deduction circus. I think we should change the Laws of Chess to disallow unsporting checkmates like these.

Jesper Norgaard
20-07-2009, 04:44 PM
How you, I or anyone else would like the laws of chess to treat the result is a little beside the point. The current laws are definite. Legal move ending in checkmate is checkmate and thus ends the game. The problem with looking back 2, 3, 4 or any other number of moves and ensuring all legal moves presents arbiting problems and so while I believe Geurt has wanted to change this law there has been considerable resistance to change.
You say that ensuring that all moves from move 1 were legal moves when checking on a checkmate presents arbiting problems. In my opinion this is only a problem if you want the arbiter to check that for each checkmate. That is an immense job. I suppose that is why there was resistance to make a rule with all moves and start position correct and legal to "end the game immediately by checkmate".

Instead I would suggest that this checking is not the arbiters responsibility, even though a checkmate is defined as only leading from legal start position and legal moves, but that any of the players can object to the checkmate by pointing out earlier illegalities. As the rules are now, the players can't object to illegal moves because the game already ended by the foul checkmate. The Devil will love this kind of legal loopholes :evil:

Desmond
20-07-2009, 04:58 PM
What if I, in a temporary brain fade, instead of opening with the English 1.c4 e5 2.Nc3, get the move order wrong and play 1.Nc3 e5 2.c4 My opponent does not notice and continues 2...Nf6.

1. Is this position illegal?
2. If I get checkmated 50 moves later shall we roll back the whole game if I realise later and want my time over again?
3. If my opponent gets checkmated 50 moves later shall we roll back the whole game if he realises later and wants his time over again?

Igor_Goldenberg
20-07-2009, 05:34 PM
I note there is a definition of position (at least with respect to rule 9.2) given which goes...


Positions as in (a) and (b) are considered the same, if the same player has the move, pieces of the same kind and colour occupy the same squares, and the possible moves of all the pieces of both players are the same.

It's not a definition of the position, it's a definition of positions being the same.



I would argue that an arbiter would just need to be conversant with the laws as they stand and the standard interpretation of them. Not all arbiters are of course.


I doubt all the arbiters (even with IA title) would accept checkmate in example 2


How you, I or anyone else would like the laws of chess to treat the result is a little beside the point.
To formulate the law you have to know what you want to achieve.

Igor_Goldenberg
20-07-2009, 05:36 PM
What if I, in a temporary brain fade, instead of opening with the English 1.c4 e5 2.Nc3, get the move order wrong and play 1.Nc3 e5 2.c4 My opponent does not notice and continues 2...Nf6.

1. Is this position illegal?
2. If I get checkmated 50 moves later shall we roll back the whole game if I realise later and want my time over again?
3. If my opponent gets checkmated 50 moves later shall we roll back the whole game if he realises later and wants his time over again?

If game continues uncorrected and ends up in a checkmate then it does not matter. I agree that a mistake must be spotted before the end of the game.
I am not happy with immediate checkmate response to illegal move though, especially if it creates an illegal position.

Rincewind
20-07-2009, 05:49 PM
It's not a definition of the position, it's a definition of positions being the same.

Yes and if two positions are the same there is no requirement for the moves leading to that position mentioned. By your alternative definition there would be a distinction between positions if the moves that lead to it were entirely legal or not.

The point is if the rules in their current form meant to ensure that the final checkmate position then it would be done by strengthening the checkmate Law (5.1) Currently it says...


"The game is won by the player who has checkmated his opponent’s king. This immediately ends the game, provided that the move producing the checkmate position was a legal move."

The final sentence would be changed to something like "Provided all the moved that lead to checkmate were legal" or "provided the final position can be obtained by a legal sequence of moves from the starting position". Depended on what you think it should be.

The fact that the laws make no mention of a position being either "legal" or "illegal" doesn't make the rules deficient. It just makes you reaching for an argument which is not there.


I doubt all the arbiters (even with IA title) would accept checkmate in example 2

I don't know on what basis an arbiter would deny a claim under 5.1 (a) and if it did occur it should be overturned on appeal.


To formulate the law you have to know what you want to achieve.

By why is what you or I want to achieve important. Chess is a game defined by it's rules which have already been specified. If they present no particular problem, why change them?

Jesper Norgaard
20-07-2009, 05:51 PM
I doubt all the arbiters (even with IA title) would accept checkmate in example 2
I agree totally, and that is another reason why we should seek more common sense in the rules, so that even the Devil can't argue for example 2. Note that Geurt Gijssen has confirmed that example 1 is a checkmate and should be treated as 0-1 in Rapid and Normal games, even though both start position was illegal and there was one illegal move before the checkmate. But he wants to change the rules as I do. I think both game 1 and 2 are plain rubbish. :wall:

Will bad Laws of Chess bring Chess in disrepute all by itself?

Jesper Norgaard
20-07-2009, 06:06 PM
The final sentence would be changed to ... "provided the final position can be obtained by a legal sequence of moves from the starting position".
...

A very interesting idea. While being relatively easy to implement and light on the poor stressed junior-event arbiters like Kevin Bonham, it would still rule out the double jeopardy in game 2. Game 1 is less of a problem because it did not consist of gamesmanship in the same degree as game 2. But I prefer to cover all the holes.

Kevin Bonham
20-07-2009, 06:25 PM
"The game is won by the player who has checkmated his opponent’s king. This immediately ends the game, provided that the move producing the checkmate position was a legal move."

The final sentence would be changed to something like "Provided all the moved that lead to checkmate were legal" or "provided the final position can be obtained by a legal sequence of moves from the starting position". Depended on what you think it should be.

It's worth noting that these two are quite different. The example given by Boris with a harmless transposition involving an illegal move 2 is one example which would conform to the second but not the first.

I quite often find in junior chess that one player makes an illegal move that creates an illegal position and then another player makes a legal move that renders the position legal (in the sense of being reachable by a legal sequence of moves).

Also, changing "provided that the move producing the checkmate position was a legal move" to "provided the final position can be obtained by a legal sequence of moves from the starting position" would open the door to checkmates with a move that was illegal in the given position, but that created a position that could have been legally reached. Another problem with "provided the final position can be obtained by a legal sequence of moves from the starting position" is that in many cases this is actually quite difficult to determine.

I am inclined to move this thread to Arbiter's Corner as most of the discussion seems to be around the ramification of these positions for Laws of Chess rather than about their status as "problems".

Jesper Norgaard
20-07-2009, 06:34 PM
I am inclined to move this thread to Arbiter's Corner as most of the discussion seems to be around the ramification of these positions for Laws of Chess rather than about their status as "problems".
Agree on that - I already killed the puzzle by presenting the solution in the first post. But I thought I had to just because the PGN recorder refused to accept the games as legal games :whistle:

Jesper Norgaard
20-07-2009, 06:51 PM
Also, changing "provided that the move producing the checkmate position was a legal move" to "provided the final position can be obtained by a legal sequence of moves from the starting position" would open the door to checkmates with a move that was illegal in the given position, but that created a position that could have been legally reached.

I think you would need both the old and the new, i.e. "provided that the move producing the checkmate was a legal move, and that the final position can be obtained by a legal sequence of moves from the starting position".



Another problem with "provided the final position can be obtained by a legal sequence of moves from the starting position" is that in many cases this is actually quite difficult to determine.

Not sure you are right, even from junior-chess. Examples? One simple one could be black pawns on a7,a6,b7 but that is easy to determine to be illegal.
This one wasn't too hard:

1.e4 e5 2.Bc4 Nf6 3.Ke2 Ng8 4.Kf3 Nf6 5.Qe1 Ng8 6.Kg4 d6+ 7.Kh5 g6#
Game 1 verified ...

Bill Gletsos
20-07-2009, 07:38 PM
It is possible to cover the 2 positions mentuoned by Jesper in post #1 without having to worry about every move in the game being legal.

This can easily be accomplished by changing Article 5.1a to the following:

The game is won by the player who has checkmated his opponent’s king. This immediately ends the game, provided that the move producing the checkmate position was a legal move, the move immediately prior to the mating move was a legal move and the position immediately prior to the mating move was a legal position.

Of course Articles 5.2a & b would also need to have the same wording added.

Kevin Bonham
20-07-2009, 07:43 PM
I think you would need both the old and the new, i.e. "provided that the move producing the checkmate was a legal move, and that the final position can be obtained by a legal sequence of moves from the starting position".

Quite aside from the above being a mouthful, I don't see the point of the "legal sequence of moves" condition. If the legality of moves other than the last is a concern, why have a rule that will capture some cases where moves other than the last were illegal, rather than one that captures all cases?

For instance my stalemate example would have remained a draw under the above.


Not sure you are right, even from junior-chess. Examples?

Sometimes I see two bishops on the same colour squares in a position where there are still many pawns on the board; obviously a bishop has slipped off its diagonal but working out whether the given position could have arisen via underpromotion to a bishop (although it obviously didn't) could take a while.

Jesper Norgaard
21-07-2009, 03:11 PM
It is possible to cover the 2 positions mentioned by Jesper in post #1 without having to worry about every move in the game being legal.

This can easily be accomplished by changing Article 5.1a to the following:

The game is won by the player who has checkmated his opponent’s king. This immediately ends the game, provided that the move producing the checkmate position was a legal move, the move immediately prior to the mating move was a legal move and the position immediately prior to the mating move was a legal position.

Of course Articles 5.2a & b would also need to have the same wording added.
This involves a new definition, a legal position, which has not been defined explicitly in other parts of the FIDE Laws of Chess, while a legal move has been defined quite explicitly. So I would rather like to work with the legal move only and leave out legal position. How about these suggested definitions:

5.1. b. The game is won by the player who has checkmated his opponent’s king. This immediately ends the game, provided that the last 2 moves producing the checkmate position were legal and did not leave it's own king in check.

5.2. a. The game is drawn when the player to move has no legal move and his king is not in check. The game is said to end in 'stalemate'. This immediately ends the game, provided that the last 2 moves producing the stalemate position were legal and did not leave it's own king in check.

5.2. b. The game is drawn when a position has arisen in which neither player can checkmate the opponent's king with any series of legal moves. The game is said to end in a 'dead position'. This immediately ends the game, provided that the last 2 moves producing the stalemate position were legal and did not leave it's own king in check.

These definitions aim to avoid the catch-22 problem that the move was not illegal in itself, but from an earlier illegal move left it's own king in check, therefore were still illegal. Just to avoid confusion. But perhaps it is unnecessary in that it must be demanded by a move regardless of the origin of the problem, to not leave it's own king in check. If we accept that, we can reduce it to the following 3 suggestions:

5.1. b. The game is won by the player who has checkmated his opponent’s king. This immediately ends the game, provided that the last 2 moves producing the checkmate position were legal.

5.2. a. The game is drawn when the player to move has no legal move and his king is not in check. The game is said to end in 'stalemate'. This immediately ends the game, provided that the last 2 moves producing the stalemate position were legal.

5.2. b. The game is drawn when a position has arisen in which neither player can checkmate the opponent's king with any series of legal moves. The game is said to end in a 'dead position'. This immediately ends the game, provided that the last 2 moves producing the position were legal.

If you made an illegal move where check was not involved, further back than the last two moves, then this is immaterial to the checkmate, stalemate or dead position. But I think that's all right. These definitions won't leave Kevin Bonham up all afternoon/evening checking illegal junior games from move 1, but would render game 1 and 2 and Kevins stalemate example (leaving own king in check when opponent immediately makes a stalemate move) all as unfinished games, i.e. the position has to be rolled back. Also leaving your king in check further back than the last 2 moves, becomes immaterial, but obviously they must have left the check situation again before the 2 last moves, or else these would not be legal.

Working with the last 2 moves required to be legal instead of last move, leaves out any possibility that one of the kings have been left in check by it's own player.

Are these adequate and acceptable law changes?

Igor_Goldenberg
21-07-2009, 04:22 PM
It is possible to cover the 2 positions mentuoned by Jesper in post #1 without having to worry about every move in the game being legal.

This can easily be accomplished by changing Article 5.1a to the following:

The game is won by the player who has checkmated his opponent’s king. This immediately ends the game, provided that the move producing the checkmate position was a legal move, the move immediately prior to the mating move was a legal move and the position immediately prior to the mating move was a legal position.

Of course Articles 5.2a & b would also need to have the same wording added.
That's much better then current FIDE rules.

Bill Gletsos
21-07-2009, 09:14 PM
Are these adequate and acceptable law changes?Actually taking your comment about legal positions not being defined into account, I would prefer the following definition of 5.1a and the addition of a new Article 4.8


Article 5.1a
The game is won by the player who has checkmated his opponent’s king. This immediately ends the game, provided that the move producing the checkmate position was a legal move, the move immediately prior to the mating move was a legal move and the position immediately prior to the mating move was a legal position.

Article 4.8
Apart from the initial position shown in Article 2, a position is considered legal if it is possible to reach the position by any sequence of legal moves from the initial position.

Jesper Norgaard
22-07-2009, 06:35 AM
..., provided that the move producing the checkmate position was a legal move, the move immediately prior to the mating move was a legal move ...

Actually I had put this a bit more abbreviated as ..., provided that the last 2 moves producing the checkmate position were legal ... The idea is to make as abbreviated and concise definitions as possible, if it will not lead to misinterpretations. But I don't think that is the case here. With 2 last moves I mean 2 last half-moves, but there are so many examples of a move being a half-move in the Laws of Chess that it should be clear.



... and the position immediately prior to the mating move was a legal position.

This also takes care of 10 white queens on the board, or black pawns a7,a6,b7 which would be illegal positions (regardless of other material). I agree we should check this too before accepting a checkmate, stalemate or dead position.



Article 4.8
Apart from the initial position shown in Article 2, a position is considered legal if it is possible to reach the position by any sequence of legal moves from the initial position.
Fixing the earlier definition.

Kevin Bonham
22-07-2009, 12:38 PM
Something I should mention as an issue with checking the last two moves:

Yes, it fixes Qxf7# from Jesper's second example, and it also "fixes" my stalemate (not that I believe it should be fixed!). Both of these get wound back to replacing the illegal move and play continues.

However, it is still a problem for junior chess. You arrive at the board to find a king is "checkmated" and in check from three pieces at once. You establish that the "checkmating" move was legal, but the move before it was obviously not. Therefore it is not checkmate, and since you have discovered that an illegal move has occurred, you have to wind the position back to before that illegal move, and if it turns out that the king has been illegally in check for several moves, you have to keep going back and back until you fix it. Again, this is time-consuming, and if the players don't actually remember the moves well enough to reconstruct, all you can really do is declare a win for the player delivering "checkmate" anyway. After all, calling "start again" against a player who has "checkmated" their opponent with a legal move just because the king has been in check unnoticed for many moves is hardly fair, and might even encourage players who are losing to deliberately put their kings in check.

I think that no matter what solution might be considered a good idea for higher levels, at junior level it should always be that checkmate with a legal move is game over whatever (other than blatant cheating) has come before.

Bill Gletsos
22-07-2009, 12:41 PM
Actually I had put this a bit more abbreviated as ..., provided that the last 2 moves producing the checkmate position were legal ... The idea is to make as abbreviated and concise definitions as possible, if it will not lead to misinterpretations. But I don't think that is the case here. With 2 last moves I mean 2 last half-moves, but there are so many examples of a move being a half-move in the Laws of Chess that it should be clear.When I composed my post #23, my original wording was similar to that but I changed it and deliberately did not abbreviate it as I wanted to avoid any possible confusion.

Igor_Goldenberg
23-07-2009, 10:45 AM
I think that no matter what solution might be considered a good idea for higher levels, at junior level it should always be that checkmate with a legal move is game over whatever (other than blatant cheating) has come before.

Junior beginners chess is not governed by law of chess anyway.

Kevin Bonham
23-07-2009, 04:40 PM
Junior beginners chess is not governed by law of chess anyway.

When I'm running an interschool tournament I generally aim to either apply the Laws properly or else specify ways in which I will vary from them, whatever the level of the players.

These are the main changes I make for the weaker interschool qualifiers:

* There is no hope of the players understanding 10.2, so in a position where a player would successfully claim 10.2 if they understood it, I will often just step in and declare the game a draw.

* 50 move rule resetting whenever things are captured or pawns move is a bit tricky for really young children to follow. Allowing 50 moves max to mate a lone king no matter what is much easier for them to understand.

* I like to encourage players to play purposively towards mate and not just go check-check-check with one piece. So I announce a rule that if a player continually checks with one piece and is not making progress, I will declare a draw before 50 moves are up.