Author: Heiner Marxen
Date: 12:22:30 01/21/01
Go up one level in this thread
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. >>>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 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. Heiner
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