Author: Omid David
Date: 16:32:30 10/04/02
Go up one level in this thread
On October 04, 2002 at 19:09:22, Jeremiah Penery wrote: >On October 04, 2002 at 18:06:21, Omid David wrote: > >>On October 04, 2002 at 17:27:05, Jeremiah Penery wrote: >> >>>On October 04, 2002 at 16:51:38, Roy Eassa wrote: >>> >>>>On October 03, 2002 at 19:18:16, Jeremiah Penery wrote: >>>> >>>>>[D]8/7p/6pP/k4pP1/b1p1pP2/KpPpP3/1P1P4/7Q w - - 0 1 > >>No blockade-detecting algorithm should announce a draw in this position, since >>the blockade can be "broken". And I think there might be a victory for white >>hidden: >> >> >>1.Qd1 >> >>A) 1... Kb5 >> 2.Qh5 >> i) 2... gxh5 >> 3.g6 hxg6 4.h7 white winning >> ii) 2... Ka5 >> 3.Qxg6 hxg6 4.h7 white winning >>B) 1...Bc6 (or any other bishop move) >> 2. Qxb3 cxb3 3.Kxb3 unclear situation > >My reasoning is that it's way harder to detect a blockade by search than it is >to detect a winning line in some "blockaded" positions. In this position, if >Qd1 Bc6 Qxb3 etc. is winning for white, the search will find it pretty quickly. >However, without detecting this as a blockade, the program will NEVER detect the >draw, and it will shuffle the pieces around forever, while declaring itself >winning by 6 pawns or more. Either way, the end result will be a draw. > >My 'algorithm' is a pretty simple thing. I just wanted it to be fast, and not >miss any cases, though I didn't care too much for false cases (because of the >above). Unless my thing is 100% correct, and never misses any potential >blockade draws, there will be error anyway (without the algorithm, you will say >+6 in the position above, and many similar positions, though it is a draw - with >the incorrect algorithm, you may say draw in some winning position). > >If there are cases where my stuff is completely and totally wrong, I will try to >fix it. Otherwise, I'll take some inaccuracy and be reasonably happy that it >works most of the time. Your perspective is really interesting, which allows a certain amounts of "unharmful" inaccuracies. My method on the other hand, refrains from declaring a draw, even if it's 99.99% sure that it actually is. Anything less than 100.00% accuracy, and the returned answer will be "I don't know!"
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