Author: leonid
Date: 13:24:04 01/21/01
Go up one level in this thread
On January 21, 2001 at 15:22:30, Heiner Marxen wrote: >On January 21, 2001 at 14:13:30, leonid wrote: > >>On January 21, 2001 at 13:44:00, Heiner Marxen wrote: >> >>>On January 21, 2001 at 13:16:22, leonid wrote: >>> >>>>On January 21, 2001 at 12:43:34, Heiner Marxen wrote: >>>> >>>>>On January 21, 2001 at 11:56:09, leonid wrote: >>>>> >>>>>>Hi! >>>>>> >>>>>>This mate position is very handy when you want to check the limits in your >>>>>>program. It is amusing also. Number of legal moves for both sides is slightly >>>>>>over one hundred. >>>>>> >>>>>> knq3q1/rq1q1qbQ/Qq2Q3/1Qn1Q2B/Q1qN1Q1r/4K1B1/1q4QR/1N1q3Q white to go. >>>>> >>>>>A hint to you, Leonid: if you like to see a diagram for the notation above: >>>>>(1) Stick a [D] directly before the FEN string, >>>>>(2) append (blank seperated) colour to move, i.e. b or w >>>>>(3) append (blank seperated) castling rights: - for nothing, KQkq or part >>>>> of it for white/black king side/queen side >>>>>(4) append (blank seperated) e.p. info: - for "no e.p. possible" >>>>>You can look up the details in the FEN standard, part of the PGN standard. >>>>>Look at the line below, which I typed in, and see the diagram, provided not >>>>>by me, but by the CCC web server, which recognizes the [D] and FEN after it, >>>>>and inserts the graphics. You can do that also. >>>> >>>>Thanks! Will try to use it the next time. >>>> >>>>Leonid. >>>> >>>> >>>>>[D]knq3q1/rq1q1qbQ/Qq2Q3/1Qn1Q2B/Q1qN1Q1r/4K1B1/1q4QR/1N1q3Q w - - >>>>> >>>>>Chest says "no mate in 9" (216 seconds, K7/600 335MB hash). >>>>>I will ask for more depth... >>>> >>>>Are there no mistake? You have really 335Mb hash? >>> >>>Yes! :-) >>>I bought 512 MB. Was a bit expensive, but my monitor costs even more. >>>And on work I have seen what 512MB can do to big Chest jobs, so I really >>>wanted to have so much memory. I like it :-) >> >>And what the monitor you have? 21 inch? >> >>The last time, around 3 months ago, I bought my last 17 inch. Very cheap and >>very good. My next dream is new computer. I need it for my programming. > >It is a 15.1 inch TFT screen. It had to fit into this tiny room, where >my computer is placed. I am very satisfied with it, but it is not cheap. Ha! You are much happier that I expected. This is the best monitor that you can have. No radiation! For somebody that work for hours it is more that simple elegance. I bought my 17 inch since I was not able to spend money on LCD. >>>>216 sec for 9 moves like very good. I went, by brute force, only up to 7 moves. >>>>It was already 2 min. 19 sec. But for this position, which look very heavy, >>>>branching factor was very normal. Like what you can expect from usual forced >>>>mate position. >>>> >>>>4 moves - 0.77 sec >>>> branching factor 5.8 >>>>5 moves - 4.39 sec >>>> 5.3 >>>>6 moves - 23.02 sec >>>> 6.1 >>>>7 moves - 2 min 19 sec >>> >>>Yes, black has also 9 queens, and whites king is exposed. If white does >>>anything not really forcing, black will start to force, or even mate. >>>Therefore the search trees can be small in many branches. In 17% of all >>>considered cases, black mates white! (yes, Chest tries that sometimes) >>> >>>Here are my numbers: >>> >>># 1 0.00 0.87 1- 0 >>># 2 0.01 1.00 1- 0 >>># 3 0.03 0.96 107- 0 >>># 4 0.19 1.04 819- 0 >>># 5 0.87 1.23 4167- 0 >>># 6 3.73 1.48 17787- 0 >>># 7 14.90 1.79 72503- 0 >>># 8 56.43 2.17 290160- 0 >>># 9 213.00 2.57 1142162- 0 >>># 10 831.85 2.90 4544295- 16385 >>>(depth seconds speed node in node out >> >>Pretty good branching factor! > >Yes, and here is the next line: ># 11 3686.85 2.90 20110217- 11363105 > >Chest does not find any mate in 11. > >>>>Leonid. >>>> >>>>>Heiner >>>>> >>>>>>If you will solve, it will be nice if you will indicate your result. >>> >>> >>>Is there any forced solution, at all? Depth=11 will take around an hour, >>>and I will not go much further, if there is no real chance. >> >>For 11 moves I don't know. My solved it by selective only at 12. Actually, this >>position is more that strange. Solution was found by the most easy level in >>selective search. Because of very good for me branching factor, I expected it >>will be instant. It was not so. It took 2 seconds. >> >>Leonid. > >Fine, so I stop this, now. Looks like there is no shorter mate, >which is not surprising for a position like this one. I am lucky that you found that there is no mate in 10. So, it is pretty rare position. I not created that many that goes so deep. Will save it in my archives. I use them when I change something in my chess solver. It could be that after a while I will do this. Then they will help me in debugging my code. >I just asked crafty 17.7 for a depth=1 analysis, and even after 3 minutes >I still see no output ;-) Obviously the quiescence search is exploding. > >Can you give some PV for the forced #12 line? Just curious. For sure! Move is white queen A6-A7. Leonid. >Heiner
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