Author: Albert Silver
Date: 13:20:19 08/09/04
Go up one level in this thread
On August 08, 2004 at 15:33:10, Robin Smith wrote:
>On August 08, 2004 at 02:36:08, Albert Silver wrote:
>
>>>On August 07, 2004 at 16:49:52, Robin Smith wrote:
>>>>Nice analysis Uri. Only one problem. How does White win in the final position of
>>>>the main line, after 10...Rxe8? I think Black can set up a fairly easy fortress
>>>>draw. I see no way for White to make progress in the queen versus rook and
>>>>knight ending. Black will leave the knight on f6, and the king will go to h7,
>>>>guarding the g-pawn while avoiding checks from the queenside. Black's king-side
>>>>is totally secure.
>>
>>I disagree. I haven't necessarily analyzed to a 1-0, but I can break the
>>fortress in any case. Bringing the king to c3 is completely useless as you have
>>shown. I think the strategy is simply that of 'two weaknesses'. Black can't
>>protect the king AND the queenside pawns all at the same time. At least, it
>>isn't clear to me how.
>>
>>Bring the white king to the kingside, and with the queen threaten to bring the
>>white king to mate threatening proximity (g6 for example). Black cannot simply
>>stay put, and this should allow white to win. An example might be (following
>>your initial line for a bit):
>>
>>11.Kb1 b3 12.axb3 axb3 13.Qf2 Rb8 14.Qe1 Kh7 15.Qc3 Rb6 16.Kc1 Rb7 17.Kd2 Rb6
>>18.Qc5 Rb8 19.Qd6 Rb5 20.Ke3 (here is where I deviate) Kg6 21.Kf4 Rb7 22.Qa6 Rb8
>>23.Qd3+ Kf7 24.Kg5 Rb7 25.Qa6 (now the Black rook is overloaded and has to cover
>>both the 7th *and* protect the pawns) Re7 26.Qb5 Re3 27.Qb7+ Re7 28.Qxb3...
>>There's a lot of work to do still, but now White also has the b-pawn as
>>leverage.
>>
>> Albert
>
>Hi Albert,
>
>You are probably right. I had not looked at it closly enough. But neither do I
>see how White can break the fortress without White giving up something in
>return. I am pretty sure Black's king needs to stay on or near the h-file, to
>avoid queen checks from the side, as I mentioned in my 1st post. Thus in your
>analysis, after 11.Kb1 b3 12.axb3 axb3 13.Qf2 Rb8 14.Qe1 Kh7 15.Qc3 Rb6 16.Kc1
>Rb7 17.Kd2 Rb6 18.Qc5 Rb8 19.Qd6 Rb5 20.Ke3 (which I agree is a much better try
>for White) 20...Kg6 21.Kf4 Rb7 22.Qa6 Rb8 23.Qd3+ here I think your 23...Kf7 is
>a mistake, allowing the queen to threaten to fork the king and rook from the
>queenside, and thus winning the b-pawn outright. However are your sure White can
>win after 23...Kh6!? White is probably still winning, but it is not 100% clear
>to me. How would you continue the analysis after 23...Kh6. The only lines I have
>found where White can win the b-pawn involve Black winning the d or f-pawn in
>return, when things get a little messy.
>
>-Robin
Hi Robin,
I took a look at 23...Kh6 and failed to see the greater problem.
[D]1r6/6p1/5n1k/3p4/3P1K2/1p1Q1P2/1P6/8 w - - 0 24
To begin with, Kh6 didn't really change much as far as I could see, since the
king is easily dislodged and forced to retreat.
After 24.Kf5 Black has to retreat with Kh7 or can play Rb7. 24...Rb7 actually
transposes as will be clear. As to 24...Kh5, it just loses the house with
25.Qe2, and 24...Rb6 fails to 25.Qd2+ Kh7 26.Qh2+ Kg8 27.Qc7
Of course, it's not really possible to cover every possible line, but here's a
sample analysis:
24...Kh7 25.Qe2 (25.Qd2 probably transposes in most lines)
[D]1r6/6pk/5n2/3p1K2/3P4/1p3P2/1P2Q3/8 b - - 0 25
a) 25...Kg8 26.Qe5 Re8 27.Qc7 Re2 28.Qb8+ and 29.Qxb3
b) 25...Rb7 26.Qh2+ Kg8 27.Kg6 (following the basic plan) Ne8 28.Qe5 Rb6+ 29.Kg5
Nf6 30.Kf5 and with the perfectly placed white queen and king, Black is running
out of moves.
[D]6k1/6p1/1r3n2/3pQK2/3P4/1p3P2/1P6/8 b - - 0 30
b1) 30...Kh7? 31.Qh2+ Kg8 32.Qc7 and 33.Kg6 +-
b2) 30...g6+? 31.Kg5 Nh7+ 32.Kh6 g5+ 33.Kh5 Rf6 34.Qxd5+ Kg7 35.Qb7+ and
36.Qxb3.
b3) 30...Rb7 31.Kg6 Kf8 (other moves aren't much better and allow Qe6 followed
by a nasty queen invasion) 32.Qd6+ Re7 33.Qb8+ Ne8 and the b-pawn is toast.
The other try of 24...Rb7
[D]8/1r4p1/5n1k/3p1K2/3P4/1p1Q1P2/1P6/8 w - - 0 25
Transposes to the diagram in line b) after 25.Qd2+ Kh7 26.Qh2+ Kg8 27.Kg6
Albert
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