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In 5.2.2 of the FIDE laws it says:

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’.

and in 9.6.2 it says

[If one or both of the following occur(s) then the game is drawn:] any series of at least 75 moves have been made by each player without the movement of any pawn and without any capture.

In a discussion we were wondering whether these rules combine, i.e. whether a position where it is not possible for mate to occur within the 75 moves rule can be considered dead. (for 50 moves we suspect the answer is no but for 75 moves it seems less clear) I suppose the same question can also be raised for 5-fold repetition.

EDIT: Since there appears to be some confusion I will add an example which is very similar to the game that caused my question. Consider the following position after White move 74: There have not yet been 75 moves without a capture or pawn move, however, it is impossible to reach a mate position within the 75 move rule. Black loses on time. Should the position have been declared dead already?

[Variant "From Position"]
[FEN "4k3/8/8/8/8/8/8/4KBN1 w - - 0 1"]

1. Ke2 Ke7 2. Kd2 Kd7 3. Ke3 Ke7 4. Ke4 Ke8 5. Ke5 Kd8 6. Kd6 Kc8 7. Kc6 Kb8 8. Be2 Kc8 9. Bf1 Kd8 10. Be2 Ke8 11. Bf1 Kf8 12. Bg2 Kg8 13. Bf3 Kh8 14. Bg2 Kg8 15. Bf3 Kh8 16. Bg2 Kg8 17. Bf3 Kh8 18. Bg2 Kg8 19. Kd6 Kf8 20. Bf3 Kg8 21. Bg2 Kg7 22. Be4 Kf7 23. Bd3 Kg7 24. Be2 Kg8 25. Ke6 Kg7 26. Bd3 Kg8 27. Bc4 Kg7 28. Bb5 Kg8 29. Ba6 Kg7 30. Bb7 Kg8 31. Bc6 Kg7 32. Ba8 Kg8 33. Bd5 Kg7 34. Be4 Kg8 35. Bf3 Kg7 36. Bg2 Kh8 37. Kf6 Kg8 38. Bf3 Kh8 39. Be4 Kg8 40. Bd5+ Kh8 41. Bc6 Kg8 42. Bb7 Kh8 43. Ba8 Kg8 44. Bh1 Kh8 45. Bg2 Kg8 46. Bf3 Kh8 47. Be4 Kg8 48. Bd5+ Kh8 49. Bc6 Kg8 50. Bb7 Kh8 51. Nf3 Kh7 52. Nh4 Kh6 53. Ng6 Kh7 54. Bd5 Kh6 55. Ba2 Kh7 56. Bb3 Kh6 57. Bc4 Kh7 58. Bd5 Kh6 59. Be6 Kh7 60. Bf7 Kh6 61. Bg8 Kh5 62. Ne5 Kh4 63. Kf5 Kg3 64. Ng4 Kg2 65. Bc4 Kf3 66. Bf1 Kg3 67. Be2 Kh4 68. Kf4 Kh5 69. Bd3 Kh4 70. Bg6 Kh3 71. Ne3 Kh4 72. Ng2+ Kh3 73. Kf3 Kh2 74. Kf2 {Black loses on time. Should the position already have been declared dead?}

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  • If, no matter what each player does, it is impossible for either player to win without a draw occurring, then there is no practical purpose in playing out the moves. However, if either player making a mistake could cause one of them to win, it should presumably be played out. Jan 25 at 20:03
  • ` it is impossible for either player to win without a draw occurring` this seems to imply that a win is possible if a draw occurs...
    – Michael
    Jan 25 at 20:33
  • Is the point of this to consider cases where time is relevant (for example, one player has only a few seconds on their clock, and the other has ten minutes, and this is a format where no additional time is added for each move)? Otherwise it seems an irrelevant distinction.
    – Joe
    Jan 25 at 22:24
  • 1
    @Joe yes, the weaker side lost on time in this situation.
    – koedem
    Jan 26 at 9:58
  • "it is impossible to reach a mate position within the 75 move rule" This is not true. At least not as phrased here. It only applies with perfect play of black, but there are plenty of legal moves that black can make to shorten the distance-to-mate to less then 75
    – blues
    Jan 26 at 13:37

3 Answers 3

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In section 3.10.1, the laws define what legal moves are:

3.10.1 A move is legal when all the relevant requirements of Articles 3.1 – 3.9 have been fulfilled.

The mentioned sections 3.1 to 3.9 only define how the pieces move, what check is, and that the King can't move if in check.

And in section 1.4, they define what a checkmate is, again using the term "legal moves":

1.4 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. 1.4.1 The player who achieves this goal is said to have ‘checkmated’ the opponent’s king

Applying these definitions to the "dead position" rule:

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.

It seems pretty clear that neither the 75-moves-rule nor 5-fold repetition should be considered since they don't impact the legality of moves.

This is specifically considering the FIDE Laws of Chess though. As far as I'm aware, USCF tournaments (and probably some others as well) have different rules for dead positions.

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  • 1
    Suppose that there was some position where the shortest possible checkmate was in 76 moves. Isn't that functionally equivalent to a dead position, since after 75 moves of no capture/pawn movement, the game is automatically drawn? Jan 25 at 19:47
  • 3
    @Kaz There are forced wins (white has mate) which occurr after more than 584 moves (!). See e.g. reddit.com/r/chess/comments/xn2uep/… - the first capture is at move 584 (although a pawn might have been moved). Anyway, based on this I think there are plenty of positions which are winning for white, but the 50 move rule makes them a technical draw
    – Ant
    Jan 25 at 22:47
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    @Ant Cool. Well I guess I stand corrected then ^^
    – Kaz
    Jan 25 at 23:29
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    @Ant, there are forced wins where it can take that long, but are there any that must take that long? That is, is there a position where it will take at least 75 moves to get to a point where a player is able to either move a pawn or make a capture?
    – Mark
    Jan 26 at 1:07
  • 3
    @Ant: yes, but that's irrelevant, this isn't about forced mate, it's about checkmate being possible. In that 584 move position white can checkmate in 3 moves if black plays badly. Jan 26 at 8:06
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First, there are positions where white can force a mate but with perfect defense by black it takes more than 75 moves to do (Ant referenced this reddit post) and that do not involve captures or pawn moves. I recall a question about these kind of situations on this site as well but I can't find it right now.

If you arrive at such a position a strict reading of the rules would be as follows. 5.2.2 says 'sequence of legal moves' so it suffices that each move individually is legal, it doesn't matter how long the sequence is. It does not say 'legal sequence of moves' which could be interpreted as accounting for the 75 moves rule. Hence the game is not a dead position, the condition for a dead position is not fullfilled. So the game continues.

If both players play perfectly 75 moves later the game will be ruled a draw by rule 9.6.2. If they only play human moves other outcomes may be possible and the game may come to a dead position a few moves later.

There is no contradiction here. One could say all 9.6.2 does is allow the players to skip doing 75 moves if they can agree beforehand that it will not change the outcome anyway. In situations where it would take more than 75 moves this shortcut is not available.

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  • That doesn't quite answer the question though, the dead position rule does not concern itself with best play from both sides but with whether there exists any sequence of moves to checkmate. I'll also note that 9.6.2 is not a decision by the players, if a position is dead, the game ends immediately, i.e. the arbiter is supposed to intervene. (in particular, a player overstepping the time limit should not lose in a dead position because the game is already over; the question was whether e.g. the given example is actually a dead position or not)
    – koedem
    Jan 26 at 10:24
  • @koedem It doesn't? It says 'the condition for a dead position is not fullfilled. So the game continues.' I will add a sentence to clarify the possible continuations.
    – quarague
    Jan 26 at 11:03
  • The example you mention is not a dead position because there exists a helpmate in 3 already. However, I am interested in the case where there does not exist a helpmate within the 75 moves rule. I.e. every legal sequence of moves leads to a draw. However, in that case only because of the 75 moves rule, if that rule did not exist then there would exist variations where one side wins.
    – koedem
    2 days ago
  • @koedom It's true that the example considers only perfect play by both sides and not help mate situations but that doesn't matter for my argument. You have to read the rule carefully, the rule does not say 'legal sequence of moves' which could be interpreted as accounting for the 75 moves rule. It says 'sequence of legal moves' so it suffices that each move individually is legal, it doesn't matter how long the sequence is.
    – quarague
    2 days ago
  • To elaborate what I meant: my question was about a scenario where there exists no sequence of legal moves that checkmates within the 75 moves rule. In the reddit example given there exists one, for example 1.Kd3 Qh5 2.Bcd2 Qh4 3.Ra1#. So the example does not match the description of the scenario I am asking about.
    – koedem
    2 days ago
2

My feeling is that it should consider the 75 move rule. The current wording strictly speaking doesn't say that, as benediktwerner's answer explains (considering it only mentions "legal moves", and the strict definition of what legal moves are does not consider the 75 move rule).

But the wording of the 75 move rule and the 5 times repetition rule use the phrase "this immediately ends the game", just like the definitions of checkmate and stalemate do. It's a final, mechanical thing.

Consider also the recent tightening up of the rules concerning draws, aimed at making it impossible to win a game that cannot be won on the board. Especially the new rule 5.1.2 -- "The game is lost by the player who declares he/she resigns (this immediately ends the game), unless the position is such that the opponent cannot checkmate the player’s king by any possible series of legal moves. In this case the result of the game is a draw." (emphasis mine). That's going quite far, that it is considered important that a drawn game can't even be won by resignation of the opponent.

Now say that 74 moves without captures and pawn moves have already been played, and in the next move it's not possible to capture anything, move a pawn, or checkmate a player. Whatever the player to move does, it's going to be a draw -- if they actually do something.

Then if either clock runs out now, it would still count as 1-0 or 0-1?

In my opinion, the spirit of the current rules is that in that situation neither player can actually win on the board anymore (the "series of legal moves" can not actually be played, because of the 75 move rule), and therefore the result of the game should be a draw. And indeed, by the dead position rule. So there wouldn't be a need to wait for a clock to fall, although in practice this won't often be noticed.

So I would claim the Preface applies:

The Laws of Chess cannot cover all possible situations that may arise during a game, nor can they regulate all administrative questions. Where cases are not precisely regulated by an Article of the Laws, it should be possible to reach a correct decision by studying analogous situations which are regulated in the Laws.

And I would consider this case to be a dead position draw.

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  • Good answer, I agree that it is in the spirit of the rules. (also relevant reference to losing on time where the same wording is used and which is very relevant to this question) Benedikt did raise a valid argument though, but interesting to see that this can be interpreted differently. :D
    – koedem
    2 days ago
  • I suppose in the end it's up to the arbiter to decide how they think about it. (at least on lichess I can tell from experience though that they do award a win in this scenario)
    – koedem
    2 days ago

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