Chess Endgame News

Three topics are discussed. First, an issue in the epistemology of computer simulation - that of the chess endgame 'becoming' what computer-generated data says it is. Secondly, the endgames of the longest known games are discussed, and the concept of a Bionic Game is defined. Lastly, the set of record-depth positions published by Bourzutschky and Konoval are evaluated by the new MVL tables in Moscow - alongside the deepest known mate of 549 moves.

WCSC 2013: the 3rd World Chess Software Championship

The 3rd World Chess Software Championship took place in Yokohama, Japan during August 2013. It pits chess engines against each other on a common hardware platform - in this instance, the Intel i7 2740 Ivy Bridge with 16GB RAM supporting a potential eight processing threads. It was narrowly won by HIARCS from JUNIOR and PANDIX with JONNY, SHREDDER and MERLIN taking the remaining places. Games, occasionally annotated, are available here.

Chess endgame news

This note defines what it means by the 'chess endgame' and looks at the frequency of sub-n-man and 'FinalGen' positions in games and studies and in the FIDE 2013 World Cup. It includes the exposition of the DTM-minimaxing line from one of the three DTM-deepest known (KQPKRBN) positions. It refines the definitions of 'longest game' and 'bionic game'. The games of the FIDE 2013 World Cup and the longest known decisive game are available here.

Rook versus Bishop

The focus here is on the influence of the endgame KRPKBP on endgames featuring duels between rook and bishop. We take advantage of the range of endgame tablebases and tools now available to ratify and extend previous analyses of five examples, including the conclusion of the justly famous 1979 Rio Interzonal game, Timman-Velimirović. The tablebases show that they can help us understand the hidden depths of the chess endgame, that the path to the draw here is narrower than expected, that chess engines without tablebases still do not find all the wins, and that there are further surprises in store when more pawns are added.

Chess Endgame News

This note includes some endgame reflections on the last World Chess Championship, an update on the search for the longest decisive games between computers, and a brief mention of the sets of endgame table (EGT) statistics recently received from Yakov Konoval (2013) and from Victor Zakharov (2013) for the Lomonosov team.

Haworth's Law

The maximum 'Depth to Mate' (DTM(k)) data for k-man chess, k = 3-7, is now available: log(maxDTM(k)) demonstrates quasi-linear behaviour. This note predicts maxDTM for 8- to 10-man chess and the two-sigma distributions around these figures. 'Haworth's Law' is the conjecture that maxDTM will continue to demonstrate this behaviour for some time to come. The supporting datafile is a pgn of maxDTM positions, each having a DTM-minimaxing line of play from it to 'mate'.

Chess Endgame News

This paper notes FIDE's 75-move rule (9.6b) and suggests some implications. It reviews two endgame-table initiatives associated with the 50-move rule. One is Huntington's mainly sub-6-man multi-valued DTM50 EGTs implemented in HASKELL. The other is Ronald de Man's WDL' and DTZ50' EGTs which introduce a 5-way evaluation of positions, and ascribe a depth to decisive positions which are not 50-move-rule wins or losses. There is also some first detail about the Lomonosov '7-man DTM EGT' team, and comments on reactions to 'Haworth's Law'.

Chess Endgame News

The DTZ metric indicates the minimaxed 'Depth To Zeroing of the ply-count' for decisive positions. Ronald de Man's DTZ50' metric is a variant of the DTZ metric as moderated by the FIDE 50-move draw-claim rule. DTZ50'-depths are given to '50-move-rule draws' as well as to unconditionally decisive positions. This note defines a two-dimensional taxonomy of positions implicitly defined by DTZ50'. 'Decisive' positions may have values of (wins/losses) v =1/-1 or v = 2/-2. A position's depth in the new DTZ50' metric may be greater than, equal to or less than its DTZ depth. The six parts of the taxonomy are examined in detail, and illustrated by some 40 positions and 16 lines. Positions, lines and the annotation of these lines are supplied in the ancillary data files.

Chess Endgame News

This note investigates the recently revived proposal that the stalemated side should lose, and comments further on the information provided by the FRITZ14 interface to Ronald de Man’s DTZ50' EGTs. The history of stalemate is convoluted, and there is an argument for computing chess endgame tables to revised rules to examine the impact of any change. The FRITZ14 interface to the DTZ50' EGTs exhibits residual 'one-out' and end-of-phase errors. Example positions are provided to illustrate the stalemate and the DTZ50' issues described.

Depth to mate and the 50-move rule

The most popular endgame tables (EGTs) documenting ‘DTM’ Depth to Mate in chess endgames are those of Eugene Nalimov but these do not recognise the FIDE 50-move rule ‘50mr’. This paper marks the creation by the first author of EGTs for sub-6-man (s6m) chess and beyond which give DTM as affected by the ply count pc. The results are put into the context of previous work recognising the 50mr and are compared with the original unmoderated DTM results. The work is also notable for being the first EGT generation work to use the functional programming language HASKELL.

WCSC 2015: the world chess software championship

This is the official report of the ICGA's 2015 World Chess Software Championship held in Leiden, The Netherlands.

Formulating generalised 'goal games' against nature: An illustration from decision-making under uncertainty in agriculture

The games-against-nature approach to the analysis of uncertainty in decision-making relies on the assumption that the behaviour of a decision-maker can be explained by concepts such as maximin, minimax regret, or a similarly defined criterion. In reality, however, these criteria represent a spectrum and, the actual behaviour of a decision-maker is most likely to embody a mixture of such idealisations. This paper proposes that in game-theoretic approach to decision-making under uncertainty, a more realistic representation of a decision-maker's behaviour can be achieved by synthesising games-against-nature with goal programming into a single framework. The proposed formulation is illustrated by using a well-known example from the literature on mathematical programming models for agricultural-decision-making. (c) 2005 Elsevier Inc. All rights reserved.

Skill Rating by Bayesian Inference

Systems Engineering often involves computer modelling the behaviour of proposed systems and their components. Where a component is human, fallibility must be modelled by a stochastic agent. The identification of a model of decision-making over quantifiable options is investigated using the game-domain of Chess. Bayesian methods are used to infer the distribution of players’ skill levels from the moves they play rather than from their competitive results. The approach is used on large sets of games by players across a broad FIDE Elo range, and is in principle applicable to any scenario where high-value decisions are being made under pressure.

Performance and prediction: Bayesian modelling of fallible choice in chess

Evaluating agents in decision-making applications requires assessing their skill and predicting their behaviour. Both are well developed in Poker-like situations, but less so in more complex game and model domains. This paper addresses both tasks by using Bayesian inference in a benchmark space of reference agents. The concepts are explained and demonstrated using the game of chess but the model applies generically to any domain with quantifiable options and fallible choice. Demonstration applications address questions frequently asked by the chess community regarding the stability of the rating scale, the comparison of players of different eras and/or leagues, and controversial incidents possibly involving fraud. The last include alleged under-performance, fabrication of tournament results, and clandestine use of computer advice during competition. Beyond the model world of games, the aim is to improve fallible human performance in complex, high-value tasks.

The role of sketches in supporting near-synchronous remote communication in computer supported collaborative design

This paper presents recent research into the functions and value of sketch outputs during computer supported collaborative design. Sketches made primarily exploiting whiteboard technology are shown to support subjects engaged in remote collaborative design, particularly when constructed in ‘nearsynchronous’ communication. The authors define near-synchronous communication and speculate that it is compatible with the reflective and iterative nature of design activity. There appears to be significant similarities between the making of sketches in near-synchronous remote collaborative design and those made on paper in more traditional face-to-face settings With the current increase in the use of computer supported collaborative working (CSCW) in undergraduate and postgraduate design education it is proposed that sketches and sketching can make important contributions to design learning in this context