Author: martin fierz
Date: 23:54:25 08/29/04
Go up one level in this thread
On August 29, 2004 at 20:06:19, Robert Hyatt wrote: >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. :) nice! interesting how some (otherwise very good) programs have absolutely no clue while others like crafty and hiarcs need no depth at all... cheers martin
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