Wednesday, April 10, 2013

Blue or Red Pill? XVIII

Right, then. You're the arbiter and you're confronted with a 10.2 claim from black that looks something like this:

When black's time elapses, after many moves, the position looks something like this:

What is the correct decision? You are advised to read the rule carefully before being in a position to act. Many hundreds of pounds are at stake.

Uphold the claim. Draw.

Reject the claim. White win.

Blue or Red Pill? Index


Jonathan B said...


To claim in the first position is ridiculous

AngusF said...

In both positions, which side is to move and what moves were played to lead to the position?

Tom Chivers said...

What's the strength of the players?

Anonymous said...

If the final position were to be played with an increment, would the game finish in any other way than a draw? Of partial relevance is that it is a draw, if you look it up in a tablebase. FIDE intend to clarify "unable to win by normal means" as being a position where there is no reasonable expectation of a win other than on time.

I don't see "Making progress" as relevant if all that has happened is a transition from a position that is unclear to one that is drawn.

So draw, not because of how the players got there, but because of the position they reached.

If FIDE ever get round to publishing them, the revised Laws of Chess from 1st July 2013 are reported to contain a clock substitution rule so that a clock with an increment or delay setting can be substituted at the initial claim.


Jonathan B said...

Finish any way other than a draw?

Clearly the pawn could be lost and then RN v R is entirely possible to lose as we all know.

Anonymous said...

It's possible to lose R v R + N, but by no means forced and much easier to defend in practice than R v R + B. There's the Polgar example with the King hiding in a corner and some positions where defending as Black with a Rook on a1 and a King on a5, you get a choice between allowing mate and Ra8 check.

But it's possible to lose any position by putting pieces en prise.


Anonymous said...

No draw!

R+N v R could reasonably be played out for a win for a long time. The strength of the players shouldn't be relevant, so zero chess knowledge should be assumed.

Of course a small increment past a certain point is the way forward for tournament games.


Anonymous said...

If an arbiter is ruling on a 10.2 claim that it isn't possible to win by normal means, then a certain level of chess knowledge is needed. In particular that a position is a draw in theory and in practice simple enough to hold. To do anything other is to allow arbiters to award wins in easily drawn K+R+P v K+R or K+P v K positions. It was part of the acceptance of quick play finishes and rapid play games that drawn positions should be exceptions so you don't automatically lose if you run out of time.

In the actual example, I think it was that Black's flag had fallen, but having previously claimed 10.2, the decision was in the hands of the arbiter as to the result who had presumably been watching since the first position.


Anonymous said...

I tried the database for KRBN v KRB. Almost all the examples with the same colour Bishops were drawn in practice. So if Black envisaged losing or sacrificing the g and h pawns, the initial 10.2 claim could be justified. You would expect an arbiter to ask for play to continue.


John Cox said...


Anonymous said...

R+N v R should never be given a draw until the 50 move rule is reached. It is quite possible to lose that endgame without an obvious blunder, as Onischuk (then around 2700) showed against Dominguez in Biel 2008.

Anonymous said...

A reconstruction of the whole Southend game has now been published at the ecforum site in the 10.2 thread.

The final position isn't as shown in the blog and with the White King cut off, even winning the remaining pawn looks non-trivial.


Anonymous said...

with the White King cut off, even winning the remaining pawn looks non-trivial

Not really. Just play Rd5, Nd3, Kf3 and that's goodbye pawn. You'd expect a 2600 GM to play those moves quickish.

Anonymous said...

Not so easy. It's Black to move in the initial position and he can play .. Rh3. If now Rd5, then Rh5 is an instant draw because both the Rook and Knight on stick on the 5th.


(The position where the flag fell has been posted on the ecforum as

White Kf2 Re5 Nc5
Black Kg6 Ra3 Pf4 )