On 11/30/2010 01:47 AM, Matthew Twomey wrote: > On Mon, 2010-11-29 at 09:10 +0100, Joost 't Hart wrote: >> On 11/29/2010 02:44 AM, Matthew Twomey wrote: >> >> Hi, >> >> Good that it works a bit more to your liking now! >> >> <zip> >> >>> I also did an analysis with Stockfish, and I am noticing one strange >>> behavior. In the annotation, it's showing a Mate-in-X that is one more >>> that it should be. For example, it's showing: >>> >>> ##### >>> 46.Ke6+ +-- >>> Stockfish 1.9.1 JA 64bit: 100:M4 >>> >>> (46.Ne4 48:M4 46..Kc8 47.Bg3 Kd8 48.Nc5 Kc8 49.Ra8#) >>> ##### >>> >>> So in the annotation, it's reporting this variation as "M4" but >>> shouldn't it be showing up as "M3"? When I look at the actual engine >>> window, it's showing "M3". It's doing this with all mate-in-x >> I am not sure we are in sync here: >> >> The line starting with 46.Ne4 is a mate in 4 moves, ending with 49.Ra8# >> I cannot see how that should be an M3. >> >> As to the engine window, which position is on the board when it shows >> M3? The position before or after 46.Ne4 has been played? >> >> Cheers, >> Joost. > Joost, > > The engine window shows M3 after 46.Ne4 has been played. I definitely > could be misinterpreting or misunderstand the exact nature of the > annotation, but it still appears inconsistent to me. Let me try to > elaborate. In the example above, I understand (correctly?) that the > first part of the annotation shows the evaluation of the move that was > actually made: > > ##### > 46.Ke6+ +-- > Stockfish 1.9.1 JA 64bit: 100:M4 > ##### > > This indicates that *after* 46.Ke6+ the position evaluates to M4 (this > is confirmed via the engine window). Now the second part of evaluation: > > ##### > (46.Ne4 48:M4 46..Kc8 47.Bg3 Kd8 48.Nc5 Kc8 49.Ra8#) > ##### > > This is showing an evaluation of M4, but here it's showing the > evaluation *before* 46.Ne4. So in the first case, the evaluation is > based on the situation after move 46 for white, and in the second case > it's showing the evaluation before move 46 for white. > > So it's possible that this is the intended behavior, but I'm just not > sure. What I though the annotation would tell me is the "score" of the > move I made, and the "score" of the suggested move. Please let me know > if you believe I'm simply misunderstanding.
Matt, It is just a detail. And no misunderstanding, I think. And I must ask you the wrong question: picture yourself in the position of the engine :-) What scid does is just autoplay the moves from the game. So every once in a while you are told to stop thinking and tell us what you consider best. So after black's move 45, you start thinking about white's 46th. And you see a mate in 4 line, starting with 46.Ne4. We stop your thought, you tell us the M4 line starting with Ne4 and we restart your thinking after putting 46.Ke6+ on the board. In this position you look for the best line for black and - after we stopped you - you report your verdict on the position. What we do now, is compare your scores of the position before 46.Ke6+ was played and after it was played. If the score-before is better (for white) than the score-after then, depending on the score difference, we annotate a variation for white's game move. Got it? So the score you see after 46.Ke6+ is really the score after 46.Ke6 was played (and assuming black will answer best). The score you see after 46.Ne4 is what the engine saw coming before 46.Ke6+ was played. As to the mating length: UCI reports the length in moves, that is, plies by both black and white. This may look confusing, depending on who has the move in the mating position. Put a position on the board in which white can produce a mate but it is black to move. Start from (edit/setup start board) W: Kb6, Rb2; B: Ka8 with white to move. The engine will report 1.Rd2 (or whatever) ... Kb8 2. Rd8# Now make the move 1.Rb4 There is still a mate (... Kb8 2.Rc4! Ka8 3.Rc8#). Look at the engine's M numbers. Cheers, Joost. > Thanks, > > -Matt > > > > > ------------------------------------------------------------------------------ Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev _______________________________________________ Scid-users mailing list Scid-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/scid-users
