I hate the threefold repetition rule

Note that the 75 move rule says "9.6.2 any series of at least 75 moves have been made by each player without the movement of any pawn and without any capture. If the last move resulted in checkmate, that shall take precedence."

The key words are "have been made", NOT "will be made".

Also note that 9.6 is not part of articles 3 and 4 and thus it is not part of the dead position rule.

I don't know about this but the last one similar that you showed was fake, because the position couldn't have been reached (including the ply count) unless the winning side had deliberately been wasting moves.

Actually, I'm kidding. This is also fake so your argument's meaningless.

"DP just looks at the tree of legal moves, which has nothing to do with 75M/3Rep termination."

Not quite as the FIDE laws are currently printed. It also looks at whether series in the the tree (which is not the game tree - serialmover mates are also series of legal moves, for example) can be played.

5.2.2 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 move producing the position was in accordance with Article 3 and Articles 4.2 – 4.7.

I know you're up to almost any challenge, but I challenge you to find a series of legal moves with which either player can checkmate the opponent's king under FIDE competition rules from this (partially specified) position.

If you believe it can't be done then you have to accept that the above blue paragraph tells you straightforwardly that the game is terminated by DP under FIDE competition rules. (It may also be terminated by other rules, but that's by the by.)

The self reference comes from the fact that the condition that a player can checkmate with a series of legal moves constrains the series to be playable under the rules, but, without any caveat, "the rules" includes the above blue paragraph.

There is no self-reference.

I pinpointed the self reference in the post to which you are replying. 

It's not germane to 75M/5R.

Legal moves are defined in Article 3. That's it. DP refers to legal moves in that context. That's it. There is no term in FIDE rules to describe the moves which are playable or unplayable due to DP.

I have used the term "legal move" exactly in that context.

I agree there is no specific term defined in FIDE to describe the moves which are playable or unplayable due to DP or due to the rules in general. Art 3 simply defines what moves are legal in a diagram irrespective of which side has the move. 

The English term playable that you have used is fine. FIDE refer only to the playabilty of series of moves leading to checkmate so far as I'm aware and use a phrase such as "a player can checkmate with a series of moves" to describe the playability of those series.

Most of the terms used in the laws are standard English with no special definition. The word "series" means just what you always thought it meant. 

But one *cannot* reuse the terms "legal" & "illegal" for those, except in a casual sense. And even there, I think I will discourage it now, because it seems as if it is genuinely confusing for some.

I would agree with that. I make a practice not to.

You have emphasized one word "can" on the the DP rule as if that means it has a certain interpretation.

Yes, as above.

But the arbiters have spoken to say how it works, and they make complete sense. Please move on.

I don't believe they have spoken in accordance with the rules.

Your position with 149 on the counter is not dead over the board. The game will stop when the next move is played.

I believe it's dead under FIDE competition rules and the game has already stopped. 

(Incidentally, endgames with moves on the clock are really interesting: there's a guy, Galen Huntington, who has put an engine together to analyze those. If this kind of position interests you, then you should really check him out. His algorithm is cool too. Of course, like most positions in a regular tablebase, they are virtually impossible to occur in everyday play, but that's never an argument against analyzing them.)

Didn't understand "endgames with moves on the clock",but it sounds interesting. I'll see if I can find it - or do you have a link?

DP & 75M is a corner case anyway, but to use your confusion over just that corner case as a justification for DP to go is absurd.

I would justify it more on the grounds that it's a rule with no stated or simple algorithm to determine if it applies. The DP & 75M question is just a consequence of introducing such a rule.

I'm not particularly dogmatic about it, but I think it should be correctly applied if it's retained and there are obviously practicality problems. I think thy should get rid of the self reference at any rate.

The idea that a "series of moves" can avoid alternative play by white & black is clever, but "seriesmover" is only a problemist term. Article 1.1 specifies that play must be alternate, and FIDE arbiter has discretion to ensure that sanity is retained.

Article 1.1 only specifies that the players must move alternately. Art 4 (touch move) is also required to ensure players move only their own pieces (though I think according to the laws White is allowed to move a Black piece from the starting position only - something else that needs fixing).

I used the term seriesmover only as a handy example, any alternation of colours would constitute a series of legal moves.

 Whenever FIDE use the phrase "series of legal moves" it's in conjunction with a requirement that a player can make them which immediately rules out series which don't alternate correctly.

OTB, the FIDE laws work *fine*, DP rule works *fine* for 25 years - please let go of all this and let's move on to the problem space where there is potentially real debate to be had.

The rule possibly worked fine for the first 19 years, because dead positions in unlimited games are almost always easy to detect. Since then I'm not so sure. I think people may have lost on time after the game has terminated under the rule. Not many of course because 75M/5R are rarely approached.

In the issues with a 75-move rule positions you mentioned the positions are not even dead (because an unlimited number of moves have checkmate as a possibility). You can look at such positions as becoming drawn, but not yet drawn. There is some confusion with the term "dead drawn" but that is not the term applied to a dead position (the term refers to positions that are almost hopelessly drawn with even only moderately skillful play, but I've won, and occasionally lost, positions that were generally considered dead drawn).

MAR, the king and pawns position you posted earlier is dead not because of a move counter, but because even with an unlimited number of moves there is no way for either side to deliver a checkmate.

I didn't say it was dead because of a move counter.

I believe it's dead because neither player can checkmate the opponent’s king with any series of legal moves. That's the FIDE definition.

I posted it as an illustration of the flaw in your argument 

Note that the 75 move rule says "9.6.2 any series of at least 75 moves have been made by each player without the movement of any pawn and without any capture. If the last move resulted in checkmate, that shall take precedence."

The key words are "have been made", NOT "will be made".

The stalemate rule is similarly worded, "has no legal move", NOT, "will have no legal move".

If you apply the same logic to the king and pawns position you refer to, then the position is not dead (contrary to what you just asserted). Both players have legal moves and the fact that they will have no legal moves when stalemate occurs you would deem irrelevant. 

In the issues with a 75-move rule positions you mentioned the positions are not even dead (because an unlimited number of moves have checkmate as a possibility).

What the FIDE rules refer to are series of legal moves and whether either player can checkmate the opponent’s king with any of them.

I'll issue the same challenge to you as I did to @anselan.

Here it is:

I challenge you to produce a series of legal moves whereby either player can checkmate the opponent's king from that position under FIDE competition rules.

Failing that, I challenge you to explain how it's not dead under FIDE competition rules according to

5.2.2 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 move producing the position was in accordance with Article 3 and Articles 4.2 – 4.7.

You can look at such positions as becoming drawn, but not yet drawn.

I can, and do, look at them as dead, hence yet drawn, under the FIDE competition rules. (Obviously neither dead nor becoming drawn under basic rules.)

There is some confusion with the term "dead drawn" but that is not the term applied to a dead position (the term refers to positions that are almost hopelessly drawn with even only moderately skillful play, but I've won, and occasionally lost, positions that were generally considered dead drawn).

But that of, course, has no bearing on the subject.

@MARattigan: I predict that anselan will have no problem meeting your challenge - since a legal move need not be a playable move by his personal "Little red book". So he will simply play past the 75M-automatic draw and hand-out a checkmate.

Neither player could checkmate with such a series, so the challenge would not be met. I think you would probably agree with that.

But your prediction is a "strawman". He has not so far done that. We should wait and see. 

By the way a legal move need not be a playable move by my personal "Little red book" either. So far as the FIDE laws are concerned it's just the moves that correspond with the definition of "legal move" in art. 3.

I once proved to you (in a set-theoretical context) that "a series of legal moves" must always be "playable" but the unplayable legal move has been deeply engraved in anselan's mind for many years and is made a cornerstone in his retrograde theories and terminology. FYI.

But I didn't follow your proof at the time and I don't believe the conclusion is correct. I would regard a seriesmover mate, for example, as a series of legal moves. In English a series of legal moves would necessarily be a playable sequence, in fact would mean that, but the term "legal move" must be taken according to the FIDE definition in interpreting the laws.

Right, let's wait and see! I just wanted to spare you the confusions I had in the past when communicating with him about "legal moves". Of course the challenge would be met by ignoring the 75M stop and continue with an unplayable legal move.

The challenge was to find a series of legal moves with which either player can checkmate the opponent's king under FIDE competition rules. That would not be met by a series of legal moves that included any unplayable moves.

That is the whole point of having unplayable legal moves! Though you need it for another purpose.

I acknowledge that the phrase "any series of legal moves" in 5.2.2 would include series with unplayable moves; these would all fail the criterion in that rule that a player could checkmate with the series. 

Note that there are no "series of legal moves" in the FIDE laws except as part of dead- or half-dead evaluations. That is precisely the context in which one could project a future where you can claim to use an unplayable legal move to manifest checkmate potential.

Noted. In each case accompanied by a phrase indicating that a player cannot checkmate with such a series, ruling out series with unplayable moves as a counter-examples.

And, I am disappointed you still believe in unplayable legal moves. It shows you never got the unassailable proof I delivered on the significance of understanding the term "series" much more than the pretty trivial "legal move".

Ah well, 'fraid so. The term"series" has no definition in the FIDE laws so I just take it as English. (Actually because of a background in mathematics, I keep typing "sequence" instead and having to correct it.)

I've done this today, and the problem is obviously fixable by modifying the stipulation to "Game drawn by repetition" instead of "Game drawn". Coincidentally, I published another problem with the same modified stip for the French retro solving tourney, where the more specific stip was felt to be clearer for the solvers. In both cases the content is intact in what might otherwise be a grey area.

Considering the subject and the fact that "series of legal moves" only feature in DP-situations, I thought it was fair to answer the challenge in that context. If you want to make a point with it, that would be the next step anyway. Otherwise I bring it up again when we are there.

"Unplayable legal moves" will never manifest in an actual game - obviously - but might be adressed for analytical evaluations to open or close doors - like a DP evaluation, like a retro-logical-analysis. In fact, the playable legal moves are the only ones which could exist in our reality to produce a legal checkmate. That is why scenario's based on unplayable moves should be completely eradicated from the DP evaluation process.

They are already.

5.2.2 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 move producing the position was in accordance with Article 3 and Articles 4.2 – 4.7.

6.9 Except where one of Articles 5.1.1, 5.1.2, 5.2.1, 5.2.2, 5.2.3 applies, if a player does not complete the prescribed number of moves in the allotted time, the game is lost by that player. However, the game is drawn if the position is such that the opponent cannot checkmate the player’s king by any possible series of legal moves.

In both cases a player cannot checkmate the player’s king by any possible series of legal moves if that series is unplayable. Obviously.

(Actually not quite obviously, but it applies to any legal position as defined in the laws.)

The FIDE description is not algorithmic but everyone reads it that way - except mathematicians of course

Which brings us to math for instance about terms like "series". All of chess is completely abstract and mathematics. At the same time it is played by "common people". I wrote some posts ago that a reasonably complex game absolutely requires a "system manual" and a "user manual". Whether or not these manuals exist and how good they are, changes nothing about the fact that chess is 100% math. And that is the only level we should address it on on this level of discussion.

The term "series" has precisely the same meaning in natural language as in set-theory. The related property of "ordering" is probably the central property of sets. Almost all sets are well-ordered before the math community gets interested.

?.

Lots of mathematicians talk about, e.g., regions in the Euclidean plane without worrying about any particular ordering of the points.

Precisely as the word "series" in natural language, it identifies a collection of items and an "ordering rule" which orders all of them. The basic "series" in chess is the "chess game" which is nothing but a "series of legal moves", the ordering rule is "the order of play".

Disagree here. Neither the dictionary nor the FIDE laws say anything about that - you just made it up.

The ordering rule is just the order you write them. The series may or may not be playable.

It's arguably true that if a move in such a series is an immediate successor of some other move in the series people might interpret it to mean it should be a legal move from the diagram left by that move, but this interpretation isn't assumed by the above rules, nor in my opinion correct.

In fact I don't think either the dictionary or the FIDE laws even assume a series has to be well ordered. Players obviously cannot checkmate with any series of moves that is not well ordered, so these are automatically excluded as counter examples to the above rules.

There is not a single doubt that the word "series" has the same structure and use in english but the people using it tend not think too much about it. It's rather simple and there are "series" everywhere. We think about it because we have a higher mission. I have written that story before and there are some more steps which I will omit now to prove that legal moves must be playable.. Only this to show there is nothing exotic going on with "series".

Note there are more places where parts of math are disguised in the rules. An interesting one are the basic FOL (first order logic) expressions used to describe the retro conventions, e.g. on castling and e.p. moves or repetitions.

Btw, chess features some of the most interesting subjects in foundational math: non-determinism (plus model theory) and the axiom of choice. Most of it awaiting a decent "system manual".

The axiom of choice would only be relevant to infinite series of moves. If an infinite series of ω moves is either prescribed or postulated under the axiom of choice there is no last move therefore no final position.

You could call that a stalemate because, with no position neither side has any legal moves (those are defined as a relation between diagrams - no diagram no moves) and, of course, neither player has a king in check - for that youl'd also need a diagram. 

Under FIDE competition rules no infinite series of moves is playable, so the question doesn't arise.