chess online vs computer

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gestalt 56 ( +1 | -1 )
Analyze this (please!) I've just finished a game of over 90 moves board #602059 . It ended as a draw (insuffient material) which I had to try and find for about 40 moves. I'm wondering whether my opponent should have been able to force the win.

I had my king and rook, he had king and queen. The position at move 57 was white Kd6, Qc8 and black Kb3, Ra4. My strategy was to keep his king from combining with the queen to force a mate, by positioning my rook on a rank between his king and mine. It worked but should it have?
jean_marc 7 ( +1 | -1 )
white should have won... After a hole lot of thinking I came up with:
65.Qd4! Ka2
66.Qf2+ Ka3
67.Qf1 Rh4+
68.Kc3 Ka2
69.Qa6+ Kb1
70.Qb5+ And the outcome is obvious.
cinabrio 28 ( +1 | -1 )
White win at move 67 Black's 65th move 65...Rh3?? is a terrible mistake, cause it breaks the basic rule of this kind of final: the player with the rook has to move his rook nearly his king. After 66.Qd2+ Ka3 white should have played 67.Qd7! with an immediate win. For example: 67...Rh6 68.Kc3 Rh4 69.Qa7+ Ra4 70.Qe7+ Ka2 71.Qe2+ followed by 72.Qb2#.
myway316 3 ( +1 | -1 )
Sorry,Jean_Marc... ...but 65...Ka2 is impossible,as the BK is already on a2,from #64.
myway316 3 ( +1 | -1 )
Nice piece of analysis,Cinabrio... ...but after 66.Qd2+ Ka3 67.Qd7,where is the win after 66...Rb3?
gestalt 22 ( +1 | -1 )
Thanks for trying but I still don't see it. Jean-marc as myway316 says your analysis is flawed because i'm already on a2 and cinabrio why would I play 67...Rh6. I would have returned to b3 (67. Qd7, Rb3) in line with the strategy i'd been using throughout.
bartlebie 2 ( +1 | -1 )
after Rb3 Qd6 wins the rook.
gestalt 0 ( +1 | -1 )
bartlebie how?
gestalt 1 ( +1 | -1 )
I've always got 68.Qd6, Rc3+
jean_marc 24 ( +1 | -1 )
Subject: Sorry... I found a type errors in my last posting.
In the game notation the number of the first move should be 67 instead of 65.

cinabrio
>>>5...Rh3?? is a terrible mistake<<<
Can you suggest another move instead?

Continuation off 67.Qd7 could be Rh4+
68. Kc5 Rh2
And no quick mate in sight.
bartlebie 19 ( +1 | -1 )
Ah sorry, I thought it was g3. Excuse me.
I'd prefer Qd6 Ka2 Qd1. The idea is to get the white King to c3, so the black king is threatened to be mated from two sides. e.g. after Rb8 Qd7 black seems not to be able to chase the King away from c3.
gestalt 74 ( +1 | -1 )
None of the analyses here by bartlebie or jean_marc seem to actually force a mate, because none of the responses that you are relying on black to make represent blacks best move. In each case black has a better alternative. I think black can force defend its position quite adequately (thats not to say that my chosen moves were the best for black). As long as the rook occupies a position that is both safe and stops the white king from getting near the black and avoids getting caught in a pincer this game could go on for ever without a win. The rook of course is able to threaten a pin on king and queen if they ever occupie the same rank or file.
jean_marc 7 ( +1 | -1 )
gestalt ? >>>In each case black has a better alternative<<<
plz, give me an example.
calmrolfe 4 ( +1 | -1 )
Howsabout 66 Qd2+ Ka3
67 Qd4 Ka2
68 Qf2+ Kb1
69 Qf1+ and wins rook

Kind regards,

Cal
gestalt 2 ( +1 | -1 )
Jean_marc what about Qf1, Rg3
gestalt 10 ( +1 | -1 )
calmrolfe The king would never go to b1 it is obviously a bad move and it has other options. I had a similar scenario on move 69.
kingslinger 45 ( +1 | -1 )
I put Fritz on your game.... And it immediately found a forced win on move 67. Qd4! wins in all variations (all legal variations calculated by Fritz).

Here is an example.67.Qd4 Ka2 68.Qf2+ Ka3 69.Qf1 Rh4+ 70.Kc3 Ka2 71.Qa6+ Kb1 72.Qd3+ Ka2 73.Qc2+ and white checkmates on next move. I went over all the variaitons and white can either force the win of the rook, or force checkmate, there are also endgame books showing that white has a forced win with Q vs. R, but the win is extremely difficult and many times in actual games, black gets a draw due to the 50-move rule, etc.
gestalt 4 ( +1 | -1 )
Jean_marc ignore that last suggestion
jean_marc 1 ( +1 | -1 )
I coudn't :) since
69.Qf1 Re3
70.Qa1#
jean_marc 4 ( +1 | -1 )
Dammit! :( more type errors.
I meant
69.Qf1 Rg3
70.Qa1#
caldazar 19 ( +1 | -1 )
65... Rh3 is not really a mistake, since the "best" move, 65... Ra8, doesn't hold out much longer anyway.

kingslinger's analysis contains a few slight inaccuracies but is essentially the correct winning sequence.
kingslinger 29 ( +1 | -1 )
innaccuracies? I just gave an example of one possible line, after clearly stating that all lines lose for black after 67.Qd4!, there are so many possible lines, that I just gave one example of a way black might try to defend...White plays perfectly in the line I give.
calmrolfe 16 ( +1 | -1 )
gestalt I think my analysis is absolutely correct. If the King had chosen to go back to a3 it loses almost immediately
Qf1 Rh4+
Kc3 and Black faces immediate mate

Kind regards,

Cal
judokausa 46 ( +1 | -1 )
lets look a bit farther back First it is a fact that Q vs R endings can be won but as someone mentioned it can be a very tedious process so why not avoid it all together. 54. f6 would have won out right. (No freebies) one pawn queens the other is kept for a future queen.
if you really must know here is a site in the ideas behind winning the QvR ending
chess.spacecoast.org/ziatdinov/QvR1.html
cinabrio 0 ( +1 | -1 )
Response to myway316 66.Qd2+ Ka3 67.Qd7! Rb3?? 68.Qd1! +-
cinabrio 6 ( +1 | -1 )
gestalt 67.Qd7! Rb3?? loses the game, although this is your "strategy".
sneaky 39 ( +1 | -1 )
queen vs rook Queen vs rook is ALWAYS a win for the queen, but
in practice it's one of the hardest endings to master
and even GMs don't find the best continuations. I
forget which GM it was who was unable to beat a
computer after achieving a QvR ending,
demonstrating how very tricky it is to win this kind
of thing when the inferior side puts up the best
defense.

Capablanca in "Chess Fundamentals" has a good
section on this ending.
jean_marc 28 ( +1 | -1 )
Karpov & Kasparov. check the link that was provided by judokausa :
chess.spacecoast.org/ziatdinov/QvR1.html

gestalt 30 ( +1 | -1 )
Thanks everyone Thanks for the analysis. Now that I know that Q v R should be a win for the queen albeit sometimes a complex one I have a slight moral dilema.

Next time I find myself in the same position should I resign honourably or should I try to defend it and try and frustrate my opponent into a drawn position.
jean_marc 10 ( +1 | -1 )
resign? never...
If your opponents wants to win then he/she need to prove their endgame skills.
astinkyfart 22 ( +1 | -1 )
another idea from a.p.i.

Instead of 85. Qc3, 85. Qh4+ Kb1 86. Kc3 is winning. There are several possible continuations.
a) Ra2?? 87. Qd1#
b) Re2?? 87. Qd1+ (^Qxe2) +-
c) Rf2 87. Qd1+ Ka2 88. Qd5+ c.) Ka1 89.Kb3! (Qd1#, 89...Rf1 90. Qa5-a2-c2, 89...Rb2+ 90. Ka3 +-) c..) Kb1 89. Qb7+ Ka1 (Rb2?? 90.Qxb2, Kc1?? 90.Qh1+) 90. Qa7+ (^Qxf2) +1
d) Rg2?? 87. Qe4+ (^Qxg2) +-
e) Rh2 87. Qe4+ Ka1 (Kc1?? 88. Qf4+[^Qxh2], Rc2+?? 88.Qxc2+) 88.Qa8+ Kb1 (Ra2?? 89.Qh1#) 89. Qb8+ (^Qxh2) +-
f) Rb8 87. Qd1+ Ka2 88. Qd5+ +- (same pattern as note c)
g) Rb7 87. Qd1+ Ka2 88. Qd5+ +- (same pattern as note d)
h) Rb8 87. Qd1+ Ka2 88.Qd5+ Ka1 89. Qh1+ Ka2 90. Qh2+ +-
(same pattern as note e)
-----------------------------------------------------------

cavturbo 26 ( +1 | -1 )
If you go back to move 89 and he'd moved Qb3+ instead of Qd1+ white would of won whichever way black moved his king. If he used the rook to cover it would be mate in about 7.

Or on move 91 Qe3 would also have won him the game. His move of Kb5 is the killer which gifted you a draw.