This thread seems to have a 10.2 offshoot
Alex McFarlane wrote:When deciding 10.2 claims a useful rule of thumb for the arbiter is - "If you have to think about it, then give a loss".
This, of course, is a simplification but a good principle to go by.
This is one thing an arbiter cannot do. Under a 10.2 an arbiter may declare a draw or disallow the 10.2 claim and leave the result to be determined by the normal rules; he cannot directly award a loss.
Returning to the main subject:-
GraemeTelBuckley wrote:David Sedgwick wrote:GraemeTelBuckley wrote:1.I grew up believing that K+N was not mating material but now I believe it is if you are v K+N (or something similar).
2.It follows that I grew up believing that K+2N was not a win v K if K flag fell but if you had K+2N v K+P then you win if K+P flag falls.
The point seems to me that I grew up believing that mating material was meant to be you could force mate with a move to go, so K+P was always a win if opponent's flag fell because you can promote to a queen and force mate. K+2N was not a win because you cannot force mate.
I am interested to know when this rule changed or did I grow up misunderstanding something?
Okay, I hope everyone is with me so far.
3. What about K+B v K+R+P and K+R+P flag falls, does K+B win on time because of underpromotion and helpmate?
Does it depend on the type of tournament? (e.g. standard play, rapid, British, International...)
All of the above assumes no draw offers have been made.
I'm not sure I am still with you, but the Laws have been changed in this regard since the 1980s. I can't recall exactly when.
Let me try to be clear.
In (1), what I now believe to be the case is that K+N can win on time v the whole army (because of the helpmate idea). The player with the whole army may not be aware that by not offering a draw they risk losing on time because they may overlook the helpmate idea and the change of the rules in the 80s or whenever, so they may think (incorrectly) that flagfall = draw.
In (2), if you have the lone K and just a few seconds, then you will inevitably lose on time. A draw offer does not help you unless you have enough time to make lots of moves. Before the rule change in the 80s, I believe that your flag could fall but you would have been given a draw because 2N+K was not mating material then but it is now.
Am I right about the above?
And point (3) has been answered by two people (thank you) but I am still wondering if there are any other exceptions (other than those in the MCCU rules).
Graham your memory is not playing tricks on you.. If you came away with the view that K+2N v K was insufficient for a win after a flag fall you probably formed that view after a tournament using earlier FIDE rapid rules after 1985, BCF Rapid rules at some time after 1995 or FIDE Blitz rules during the period 1997 – 2001. Alternatively it may have been a tournament which used their own rules.
Without going fully into the history, most of what you say about rules employed during 1980 – 2000 is correct. It was often not clear to players and arbiters what the correct rule versions were and which rules were being used in tournaments. It was a bad time to learn the rules. The internet was not readily available during most of that period and printed copies of rules were not widely circulated; those that were, were often out of date.
During that period the 4 main situations for flag fall as covered by the FIDE rules ie. Longplay intermediate time control, QPF, Rapidplay and Blitz often had different conclusions. This was further confused by BCF rules for Rapidplay, QFP and Blitz existing concurrently with the FIDE rules and often differed as regards flag fall from the FIDE rules. During that time all 7 versions were revised at least 2 or 3 times often altering the flag fall rule.
There were further complications as some adult Rapidplays were played under Blitz rules, some junior Rapidplays played under QPF rules and the WCU had a slightly different view on the then 10.2 rule. In addition Leagues often wrote their own QPF rules based on Blitz rules and Tournaments often used new BCF rules before the official release date
(, as described here on the CAA website ). (This document also contains some Arbiter 10.2 views). There were also some rules for bullet chess and 5 minute chess (which should really have been the same as Blitz rules). I cant remember much about the last two rulesets, which may not have been official rules, so wont comment. If you played in a Rapidplay in early 1995 the rules used could have been one of 4 sets : FIDE rules, BCF Rapid rules , the proposed new BCF Rapid rules or Blitz rules.
It is astonishing that it took almost 20 years for the rules to be revised to where we are now which is that if an opponents flag falls a player wins unless there is no legal continuation of moves resulting in a checkmate position in favour of the player, including by helpmate if necessary. This doesn’t apply if an arbiter observing a 10.2 claim decides a draw is appropriate when the flag falls.
I think the rules could be better worded to replace the misleading term “mating material†as the pieces themselves may be incapable of mating in any legal way due to their placement.
POS1.jpg
In this comical “whole army†v K+N after a W flag fall, with W to move, B wins but only draws if the BN were instead on a1.
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