Sunday, January 15, 2017

Development version 11.00.06: stability control in game analysis

When analyzing a game, a tab has been added that is the Stability control.
After finishing the analysis of a position with the parameters of time and depth indicated, it continues to analyze until in the last depths the calculated move is the same and the difference in the evaluation does not exceed the number of centipawns indicated.
This option can add a lot of time to the analysis of certain moves. Perhaps some option must be added to control this.


  1. Hello!

    Thanks for the awesome program, extra thanks for keeping it free & open source.

    Bug report: "GM Engines" & "Tourney-Elo" don't work in version 11, nothing comes up.

    Feature request: most tactics problems are about offense, that is, the side to move can win something. but for many (myself included), defense is more critical, that is, seeing the threat in advence and doing something to avoid the danger (and not blundering). so maybe it's possible to add an option to duplicate the problems, with the side to move reversed?

    Thank you!

    1. The next update fix that problem.

      In relation to the feature request, there is not defense in the tactics included with the program.
      It is necessary a collection of tactics, like positions that are draws to the engine, and fight against it, maintaining the draw. Perhaps this is a good training to think.

  2. This is actually not limited to draws. As an extreme example, in
    4k3/1ppppppp/8/8/8/8/8/R3K3 b Q - 0 1
    black is in fact ahead, but anything other than moving the d-e-f pawns loses on the spot to Ra8#
    This position is not realistic, of course, but serves well to illustrate the point. The point is, many (most?) novice's games are lost not by slowly losing a drawn game, but by critical blunders, often giving away a won game.
    Maybe a good start would be mass-analysing a huge collection (from FICS etc) of players bellow a certain Elo (say 1600) for blunders, and save that as a tactics file. I just don't have the CPU for that...

    One more recommendation: Chess Vision exercises, as explained in De la Maza's Rapid Chess Improvement, Wetzell's Chess Master At Any Age, Heisman's Guide to Chess Improvement, and many more. Some examples: given a position, rapidly indicate which pieces & pawns are attacked (& how many times). given a square name (such as f4), quickly answer its color (dark) and location (crossroads of g3-e5 and e3-g5), and what squares a knight positioned there would attack (e2, g2, d3, h3, d5, h5, e6, g6). given a position, and then a few moves (in algebraic notation), create the resulting position. And so on.

    Thank you again!

    1. I like the idea that the user in a draw position maintain the draw playing against stockfish by example.
      Your idea is in a position a FICS player has a mistake, then this position is presented to the user, to test if select the best option, ok ? For this there is an automatic way in the program to get this positions (Utilities/Massive analysis in reading a PGN file).
      In relation to chess vision, there is a training, Resources for zebras, the board at a glance that is a primitive way to work in chess vision.
      Also Moves between two positions.
      But as you says there are a lot of more.
      I take note of that.

  3. Of course maintaining a draw against stockfish is a very good idea. maybe I can add to that maintaining a narrow win, for example in grandmaster games (they typically resign before the the win is obvious).
    I know about Massive analysis in reading a PGN file (and it's great!), but I don't have a good enough computer to analyze thousands of games, so my idea was maybe the Lucas Chess team could do it and distribute it within Lucas.
    One more comment about analyzing games: a blunder is defined as doing a move that loses a certain number of centipawns from the previous ply, so if my opponent blundered and I didn't take advantage, that's my blunder. This is fine, but sometimes I want to see just my own blunders (not missed opportunities), so maybe there should be an option to define a blunder as losing a certain number of centipawns relative to my previous move?

    Thanks for the pleasant discussion.

    1. I have to think about your idea of detect blunders.