Author: Robert Hyatt
Date: 17:06:19 08/29/04
Go up one level in this thread
On August 29, 2004 at 02:36:48, martin fierz wrote:
>On August 28, 2004 at 18:40:43, martin fierz wrote:
>
>>aloha!
>>
>>after all the cloning talk, here's something to test your favorite engine with:
>>i played a weakish IM today and got the following position after 56...Qg6+
>>57.Kf2:
>>
>>[D] 8/6kp/8/3p4/1P4q1/P4p2/5K2/4Q3 b - - 0 57
>>
>>it took me a couple of seconds to see that after 57...Qh4+ 58. Kf1 Qxe1+ 59.
>>Kxe1 Kf6 black is completely winning due to the floating square (it's nice to
>>see that reading dvoretzky is some good!) and so i played that and won :-)
>>
>>interestingly, when i entered this game in chessbase running fritz7 in the
>>background, fritz didn't seem to see this at all within a minute or so. so
>>question to all: how long does your favorite engine need to see the line ...Qh4+
>>Kf1 Qxe1+ with a HUGE plus score (i.e. +9 or so - that is what my assessment of
>>the position was after a couple of seconds...)?
>>
>>i don't want to claim that this is the only win, but it is by far the easiest
>>one, and fritz 7 misses it completely.
>>
>>cheers
>> martin
>
>kurt made the (unfortunately valid) point that my original position allows black
>to win without exchanging queens. so i've modified it to exclude that
>possibility.
>
>the point i wanted to make is that human experts don't treat an exchange into a
>pawn ending as "yet another variation", instead they check such exchanges much
>more carefully. which is why i see this Q-exchange variation immediately, and an
>engine which either
>1) doesn't check trades into pawn endings properly or
>2) lacks knowledge about the square / the floating square
>will have trouble coming up with the line i gave. which also means it would have
>trouble in my next test position, which is a simple modification (i removed the
>black pawn on f3 - if 6-piece tablebases with 4 pawns were available, one could
>add another white pawn on a2/b2/b3 for engine confusion without changing the
>result):
>
>[D] 8/6kp/8/3p4/1P4q1/P7/5K2/4Q3 b - - 0 57
>
>black still wins with the Q-exchange, and he wins very easily. my fritz 7 on a
>P4 1.4GHz is showing ...Qc4 (0.00)after 6 minutes (can anybody check out fritz
>8?).
>
>so again: which engine sees this in a reasonable amount of time? to me it is
>just very astonishing that a top engine like fritz can't handle this... i'm used
>to analyze my games with fritz, and usually it finds errors i make, and not vice
>versa :-)
>
>cheers
> martin
Crafty on my dual xeon:
1-> 0.02 -5.15 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1
2 0.02 -5.25 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
2-> 0.02 -5.25 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
3 0.02 -5.05 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4
3-> 0.02 -5.05 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4
4 0.02 -5.15 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke5
4-> 0.02 -5.15 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke5 (s=2)
5 0.02 -5.05 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke5 5. Kf2
5-> 0.03 -5.05 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke5 5. Kf2 (s=3)
6 0.03 -4.99 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke5 5. a5 Kd6 (s=2)
6-> 0.04 -4.99 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke5 5. a5 Kd6
7 0.05 -4.75 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke5 5. a5 Kd6 6. b5
7-> 0.08 -4.75 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke5 5. a5 Kd6 6. b5 (s=7)
8 0.11 -4.95 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke5 5. a5 Kd6 6. b5 d4 (s=6)
8-> 0.21 -4.95 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke5 5. a5 Kd6 6. b5 d4 (s=7)
9 0.36 -4.67 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke7 5. a5 Kd7 6. a6 Kc6 7. b5+
Kb6 (s=6)
9-> 0.92 -4.67 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke7 5. a5 Kd7 6. a6 Kc6 7. b5+
Kb6 (s=4)
10 1.69 -4.65 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke7 5. a5 Kd7 6. b5 Kc7 7. b6+
Kb7 8. Kf2 (s=3)
10-> 4.79 -4.65 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf6
4. a4 Ke7 5. a5 Kd7 6. b5 Kc7 7. b6+
Kb7 8. Kf2 (s=3)
11 9.36 -4.57 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf7
4. a4 Ke7 5. a5 Kd6 6. b5 Kc7 7. a6
Kb6 <HT> (s=2)
11-> 28.97 -4.57 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf7
4. a4 Ke7 5. a5 Kd6 6. b5 Kc7 7. a6
Kb6 <HT> (s=3)
12 48.05 -4.61 1. ... Qh4+ 2. Ke2 Qxe1+ 3. Kxe1 Kf7
4. a4 Ke7 5. a5 Kd6 6. Ke2 Kc7 7. Kd3
h6 8. Kd4 Kc6 (s=2)
12 48.05 2/30* 1. ... Qf5+
Takes 1 ply here. :)
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