On reflection it would be much better to keep the draw period at 50n ply (25n moves) and just let the players claim a draw on either player's move (possibly simultaneously). KRK and KQK endings in which the stronger side doesn't "progress" would then be limited to 25 moves on a claim by the weaker side.  

I think you're being deliberately obtuse here. Unless you're a complete beginner, you know that the endgame KBN v K is a win 'always', so if the arbiter were to reject the claim after 50 moves, you can quite confident that you're actually quite close. Never mind, I used it for illustrative purposes, because the result can never stray beyond draw for the defending player.

The monster position was just another example, asking where on earth you're supposed to draw the line. The man behind the bar is going to see that it's still a win, so why accept the draw claim? With 500 moves between the last pawn move and the first capture, I dare say there's plenty of opportunities to stray off the most correct line of play (because it's so complex), but where do you the draw line? When should you no longer get an extension? The barman wouldn't have a clue.

In other words, you're weighting blunders differently depending on who claims the draw. Makes no sense.

Sorry, of course, mate in 1, but is that really the example they gave for extending it though? They just said pawn blocked beyond the Troitzky line, didn't they?

What's with this penchant for changing the move limit all the time. You'll need a reference table thicker than the official Laws of Chess handy!

With the exception of the USCF, as far as I know, there are very few chess federations that don't apply the FIDE Laws of Chess also to their local/regional/national competitions, with only minor adjustments (if any). In short, if you're playing any type of regulated tournament where you live, as likely as not, the FIDE Laws of Chess applies. Sure, you can always adopt your own rules, but as soon as you start to play nationally or internationally rated games, the FIDE Laws of Chess come into force.

Да, утомительно ...

Yes, they just said pawns blocked behind the Troitsky line. The example is mine, but falls within that rule.

Unless  you can't multiply by 25, you don't need a reference table at all. Even if you do need a table it's hardly very thick. It goes.

No. of pieces      Draw period
additional to      (moves)
the kings.

1                         25
2                         50
3                         75
4                        100
5                        125
6                        150
7                        175
8                        200
9                        225
10                      250
11                      275
12                     300
13                     325
14                     350
15                     375
16                     400
17                     425
18                      450
19                      475
20                      500
21                      525
22                      550
23                      575
24                      600
25                      625
26                      650
27                       675
28                       700
29                       725
30                       750

Entries beyond the first 6 would probably never be needed.

The rules, as I said before, should cover all situations. That includes games by complete beginners.

As I already pointed out, if a draw claim by Black in KBNK after 50 moves were rejected White could still be 33 moves away from mate. That is not "quite close" in this endgame. There would be no reason for a draw claim by White, but if it were made the same applies.

You draw the line whenever the person claimed against fails to make progress. If he continues to make progress there is no reason for the rules to interfere. The Basic Rules of the FIDE laws draw no line at all.

And of course in the situation I described in the monster position you don't accept the draw claim if the claim is made by Black. The barman doesn't grant an extension, the rules do. He doesn't need to know how to play chess.

Could you look at post #51 and understand how the rule works, please?

In practice many games would be decided by an agreed draw before even the first draw period expired.

I said many 2 knight vs pawn endgames, not all. The endgame is pretty rare and 2 knight vs pawn endgames which are only winning without the 50-move rule are even more rare.

@BonTheCat

I think you're being deliberately obtuse here. Unless you're a complete beginner, you know that the endgame KBN v K is a win 'always', so if the arbiter were to reject the claim after 50 moves, you can quite confident that you're actually quite close.

I'll illustrate by an example. The game here:

http://www.chessgames.com/perl/chessgame?gid=1533865

The KBNK ending was reached on move 126 in this position. This is a theoretical mate in 27.

After 50 moves the following position was reached, which is a theoretical mate in 19.

Under my rules White could claim no progress by Black at this point, but the claim would be rejected because Black has progressed 8 moves towards his mate. The game would continue.

In the event the game continued anyway, because Black failed to claim under the 50 move rule which was actually in effect for the game. Had he claimed, the game would have terminated in a draw at that point.

Would you call 19 moves quite close?  

Neither player here was a complete beginner. The game ended in stalemate 3 moves later (so definitely not quite close).

Numquam: Exactly. And the position taking 115 moves has pawn moves at regular intervals in the solution.

MARattigan: I don't need to look at #51 once again. Your criteria for the draw claims seem to be based almost exclusively on whether one side is theoretically winning rather than whether they've made any progress or whether they actually know anything about what they're doing. As has been pointed out repeatedly in this thread, the 50 move rule was introduced to avoid 'Sitzfleisch' being a determining factor. The vast majority of all games never get close to endgames where more than 50 moves without capture or pawn moves are needed to win. As far as I'm concerned it's completely unnecessary to set different limits depending on how many pieces are left on the board - it's not really a determining factor whether more than 50 moves are needed. One can always discuss which limit is the most suitable, and personally I wouldn't argue for more than 75.

Re #116, I've already said that if you need 50 moves to reach that position, you really don't know what you're doing, and as you can see, it took Yepishin 8 moves to drive the king to the edge (and he failed to spot the standard win after a further 8 moves). Another 42 moves later, the mate in 19 position you show comes up. Do you seriously think that's a show of progress by a super grandmaster? This is just ridiculous.

The 50-move rule is pretty clear. It is much harder to make your suggestion cover all situations. Just because you don't like the result in some very rare cases, doesn't mean it doesn't cover those situations.

I don't think that I have to explain that these endgames are rare in practice. Just take some random tournaments and check the games yourself. You'd be lucky if you can find such a game from a random sample.

It is very important how rules turn out in practice. Nobody is going to change the rules unless you can find examples in practice where the rules don't work well. Numbers do matter. Let's say they would use your rule and people don't like how it plays out in 50% of the situations where the rule is used. And the benefit is only that a few in a billion games can be won where both players played the endgame well. Then clearly it is a bad rule.

Numquam: Exactly. I play around 40 to 50 competitive games per year. It took more than 1,500 games before I reached the KBN vs K endgame (and I was closeish to getting a KRB v KR once about 15 years ago), and moreover the only tournament game of mine where the 50 move rule has a) come into play, and b) actually been applied.

But no one is perfect, you are saying the endgame should only be winnable if one player plays perfectly

When 75 moves needed just seems like is sucking all creativity out of the game of chess, might as well turn yourself into a computer completely. LGBTC

@BonTheCat

I have to say I don't understand why you appear to have so much problem with the clarity of my rule. I agree it's more complicated than the 50 move, but really no more complicated than say the castling rule.

I agree that endgames where either the 50 move rule or my proposed rule applies are rare in practice. They're both designed to cope with exceptional situations where play is pointless, but one player refuses to agree a draw. The difference is that the 50 move rule allows players to force a draw in situations where play isn't pointless.

I don't know why you would assume players wouldn't like the rule in 50% of the situations where it would apply, but I'm not advocating removing the agreed draw rule. If they don't like it they can just agree a draw. 

There's also something called insufficient losing chances, where in a drawish position, someone trying to win on time can be stopped by his opponent if there is a 90% chance that a 1500 rated player could hold the position against a 2200+ player if they both had sufficient time. That takes care of random moves in useless positions, 50 move rule is not necessary.