Let's say we have a few situations. White has all their pieces (hypothetically) and black has only:

  • N+K
  • B+K
  • N+N+K

If white were to run out of time, would each of these situations be a draw due to insufficient material? I'm wondering because let's say black were to have a forced checkmate with one of the above situations, could white deliberately lose on time and claim a draw?


lichess gets it wrong.

As it happens, White would lose all three games. With all white pieces still on the board, black has still "enough mating material" - it would actually help if White had no pieces at all!

I guess we all agree in the following position black is checkmate:

5k1K/5n1P/8/8/8/8/8/8 w - - 0 1

But this position can be reached from the examples shown. Even without pawns, it is still possible to checkmate for black:

2RKR3/5n2/3k4/8/8/8/8/8 w - - 0 1

Obviously, these cases are rather theoretical. But there are real-world situations (you need something like KRR vs KN, note that KQ vs KN is in fact drawn under that circumstances!) where this may apply. That is why the 10.2 rule (claiming draw with less than two minutes, now annex G) was established and why any higher-rated modern tournament will play with time increments.

There aren't many examples of asymmetric insufficient material. Most of the time, either both players or neither can win.

Edit: The relevant section of the rules is Article 6.9:

Except where one of Articles 5.1.a, 5.1.b, 5.2.a, 5.2.b, 5.2.c 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.

The common simplification "has not enough winning material" is not always a good one.

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  • "asymmetric insufficient material" would result in a 'dead position' and end the game immediately by the article 5.2b of the Laws. No flag fall involved. – IA Petr Harasimovic Dec 14 '15 at 8:54
  • No, symmetric insufficient material would do that. In asymmetric positions, one of the players can still win. – chaosflaws Dec 14 '15 at 9:17
  • What would be the procedure if it's not obvious whether any legal series of moves would allow the player with time to achieve victory? I think a fair rule would be to say that if one player's clock expires, the other player may make moves for both sides as long as his time is running and has not expired. In most cases, it should be sufficiently trivially easy for a player to secure a win that the opponent should resign, but a player who can't checkmate the opponent in such a situation doesn't deserve credit for a win. Any idea if any games have actually been arbitrated that way? – supercat Mar 31 at 15:07
  • @supercat The general rule is that "the claimant has to prove his claim". If the player losing on time cannot convince the arbiter the position is drawn, he should lose on time. As the decision does not have to be made immediately (ideally, not before the drawing of the next round), in complicated cases, I would let the claimant argue his case on another board or when all games are finished. If I am convinced by his argument and the opponent cannot point out a winning line for him, I would decide the game to be drawn. – chaosflaws Mar 31 at 21:27
  • @supercat However, I have yet to encounter a position at an actual tournament where deciding this question is problematic. As to whether complications did arise in professional play, that might warrant its own question. – chaosflaws Mar 31 at 21:28

I'm one of those players who have benefited from the Insufficient Mating Material rule. I was playing in a national open tournament, and had just cleared the 2-minute mark on my clock before the Sudden Death time control.

My opponent had been whittled down to a bare king, but my pieces and pawns were not coordinated enough (read: too cluttered and disorganized) to grind out a midboard mate or wedge him over to the edge of the board reliably in the time remaining.

So, I hailed a TD, and reported my intention to claim a draw based on the above rule. The TD looked the position over, saw that my opponent had no chance of winning without the clock, and ruled a draw. That saved me a 1/2 point.

The FIDE rules state (Article 9.6): "The game is drawn when a position is reached from which a checkmate cannot occur by any possible series of legal moves, even with the most unskilled play. This immediately ends the game."

I recall hearing that GM Josh Friedel attempted to claim a draw on this basis once in a game he was playing in Europe, but the FIDE rule allowed for a helpmate which was possible with the material his opponent still had (he had two knights). Friedel was ordered to play on, with a time penalty for a denied draw claim. Unsurprisingly, he lost on time.

By the way the USCF rules differ from FIDE's: It is necessary for the player with the inferior material to be able to force mate. It can't be only available through a miracle or the assistance of the opponent, and depends on the player's ability. The arbiter has discretion regarding the complexity of the mate and whether an average player of the appropriate class would be able to execute the mate. This is much more forgiving than FIDE's definition.

For those of us who aren't familiar with the theoretical draws based on material, a nice summary is presented by the E4 Email Chess Club.

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  • The USCF's rules on draws are not what they once were. Claiming a draw by insufficient losing chances is now only a variation; the standard rule is that you can't. Either way, you were in no danger of losing on time, as your opponent had a bare king, and you can't lose on time if it's impossible for your opponent to checkmate you. – D M Oct 29 at 5:03

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