Hello I have a few "edge" cases which I am quite interested what do you think about.

Note that all of those are on my understanding of FIDE chess rules and might be wrong - thank you for the correction in that case.

The game shall end in a draw if there is no legal sequence of moves leading to win (for either side)

how would you decide this as an arbiter? I believe it can be sometimes difficult to see if it's possible within the 75 move rule ...

I believe there are more such edge cases - such as that a position forcing move (or sequence of them) that leads to 5 times repeated position etc. Also note that this might be important to know is someone's time is down in an OTB tournament in such a situation.

1 Answer 1


For clarity here are the two positions:

[fen "8/1k6/8/8/6qK/8/8/8 w - - 0 1"]

and where there have been 145 half moves since the last capture or pawn move:

[fen "7b/8/8/3k4/8/3K4/8/5B2 w - - 145 1"]

This question really only gains importance if white's flag falls in the first position or if either flag falls in the second position. Then the losing player would want to quite strongly claim a draw here under article 5.2.2 -

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 think in the first position the decision is very clear cut. There is no series of legal moves leading to checkmate and the position is a draw.

The second position is slightly more problematic because it is not immediately clear to the passing observer that the 75 move rule is 5 plies away. Strictly speaking a good arbiter should not be a typical "passing observer" and should be aware of the situation. However not all arbiters are equally vigilant. Nevertheless once the arbiter's attention has been drawn to the score sheet and the 75 move rule explained the arbiter should again rule that despite the flag fall the game is drawn.

Absent a flag fall most arbiters will just say "play on" and declare the games drawn on the next ply, in the first case, and 5 plies later in the second case. It is the easiest and least controversial path and avoiding controversy is high on most people's list of priorities, arbiters included.

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    thank you, _____________ a) "with any series of legal moves" are moves going past move 75 considered not legal moves -> if they are the rule would not aply I assume - than it would be a win for any side if the flag falls. ___________________ b) I was also aming towards more complex cases where it's maybe like 20 moves away from 75 move rule and it can/can't be barely achived to reset the rule/give checkmate
    – kortyxx
    Oct 27, 2020 at 15:03

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