Author: Andreas Stabel
Date: 01:11:43 02/16/00
Go up one level in this thread
On February 15, 2000 at 17:22:40, leonid wrote: >On February 15, 2000 at 07:40:32, Andreas Stabel wrote: > >>On February 14, 2000 at 17:39:42, leonid wrote: >> >>>On February 14, 2000 at 11:29:23, Heiner Marxen wrote: >>> >>>>On February 14, 2000 at 05:08:22, Andreas Stabel wrote: >>>> >>>>>On February 13, 2000 at 18:02:20, James T. Walker wrote: >>>>> >>>>>>On February 12, 2000 at 10:18:44, leonid wrote: >>>>>> >>>>> >>>>>> >>>>>>This is from George Koltanowski's book "TV Chess". It is a mate in 10 with 4 >>>>>>underpromotions to a Knight. It is one of my favorites. I was surprised to >>>>>>find in the late 80's that the Fidelity Champion Sensory Challenger would solve >>>>>>this problem in about 42 seconds. Todays programs will solve this in less than >>>>>>1 second. >>>>>> >>>>>>[D]7K/P1p1p1p1/2P1P1Pk/6pP/3p2P1/1P6/3P4/8 w - - 0 1 >>>>>> >>>>>>Jim Walker >>>>> >>>>>This is a nice variation on the same position the I made from another >>>>>variation on this position :) >>>>>Note the nice queen moves at the end, and that promoting to a knight the >>>>>third time will not work. >>>>> >>>>>[D]8/1p1p1p1p/3P1P2/pp5P/kp6/1p4P1/1P4P1/2K5 w - - 0 1 >>>>> >>>>>Regards >>>>>Andreas Stabel >>>> >>>>Ah, I like it! It is a mate in 16. Chest on P/133 with 10 MB hash table >>>>needs 1.15 seconds to find the main variation: >>>> >>>> g4 h6 g5 hxg5 h6 b6 h7 g4 h8=N g3 Ng6 fxg6 f7 g5 f8=N >>>> g4 Ne6 dxe6 d7 e5 d8=Q e4 Qb8 e3 Qxg3 e2 Kd2 =*= Qxe1 g3 Qa1# >>>> >>>>Complete solution tree in 1.67 seconds. Wow. >>>> >>>>Heiner >>> >>>Now I see why my logic could not touch it. It is too deep to see. My mate logic >>>goes only 13 moves deep. But compose position as deep as 16 moves is a real >>>challenge. Well done! >>> >>>Leonid. >> >>Thanks, my only regret is that this is an illegal position. The configuration >>of black pawns can never be reached in an actual game. >>Notice the nice mate in 6 for white if black answers 1. g4 with 1... b6 ! >> >>The position I made this problem from is the following with white to move >>and win. Note that it is NOT a mate in n problem. >> >>[D]8/pp1p1p2/1p1P1P2/k7/8/1p4p1/1P4PP/2K5 w - - 0 1 >> >>Here it will work to promote to a knight the last time also, but if you >>choose to promote to a queen, the mate will be the same as in my mate in >>16 problem. This is of course asuming that plays for a stalemate, and close >>up the king position completely. >> >>Best regards >>Andreas Stabel > > >Sometime very impossible position is good to have when you write your logic. It >permit to find, generally speaking, if logic work well. Position with 9 queens, >6 rooks... I created many positions when I wrote my initial logic that generate >legal moves. To see if everything goes well, positions that contain inevitable >mate were ideal for debugging. > >Just by curiosity, how you reached your quit sofisticated positions, by "hand" >or with usage of some program? Did you came to the creation of the position my >way? I want to say that you started writing some logic and solving the positions >was your way to find some responses. Or you just created your positions for fun >since the beginning? > >Regards, >Leonid. The last of the positions above: 8/pp1p1p2/1p1P1P2/k7/8/1p4p1/1P4PP/2K5 w - - 0 1 was a problem I was shown some years ago. I liked it, but discovered that it was not a forced mate because black doesn't have to play for a stalemate. In addition I really love the version where you choose a queen on the last promotion, so I started fiddling with the position, first to make it a forced mate in as many moves as possible. When I had done this I found that adding the pawn at b7 giving the position: 8/1p1p1p1p/3P1P2/pp5P/kp6/1p4P1/1P4P1/2K5 w - - 0 1 which is shown above, would force white to choose a queen on the last promotion. This was just a lucky accident, but perhaps what makes this mate in 16 a real beauty to me. The draw-back is of course that this position could never be reached in a real game and that the version where you choose a knight at the end, which is also beautiful, was lost. Perhaps a small consolation is that the variation where black answers 1. g4 with 1... b6 gives a mate in 6 with a similar theeme. I think the whole process of thinking about this position and fiddling with it perhaps took 5-10 years :) Regards Andreas Stabel
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