Comparing Chess Openings Part 3: Queen's Pawn Openings

Abstract

A dual engine experimental design for comparing chess openings was described in a previous paper (Munshi, Comparing Chess Openings, 2014). It is used in this paper to study ten chess openings that are initiated with the queen's pawn move 1. d4. One of the openings is identified as the mainline and the other nine as variations from the mainline. Five of the variations are found to be benign innovations and the other four are deemed to be failed innovations. The findings are mostly consistent with expert opinion. The primary purpose of this paper, however, is not these specific findings but rather the further development and verification of an objective and quantitative methodology for the evaluation of chess openings in general 1 . This paper is the third of a series in a study undertaken to develop a generally applicable methodology for the objective evaluation of chess openings. The proposed methodology uses controlled experiments with chess engines to compare chess openings. The first paper in this series (Munshi, A Method for Comparing Chess Openings, 2014) presented a single engine experimental design (SED) to compare ten openings that are initiated with the King's pawn move 1. e4. It demonstrated that the proposed methodology is able to discriminate between known strong openings and known weak openings. The advantage of the SED is that it removes the difference in playing strength from the experiment and isolates the effect of the opening; but the disadvantage is that the same engine playing both sides of the board may introduce an engine bias in the data by not playing a sufficiently diverse set of opening variations. Subsequently, a dual engine design (DED) was proposed to address the issue of engine bias (Munshi, Comparing Chess Openings, 2014). The second paper showed that there may have been a propensity for engine bias in the SED and that the engine bias problem is mitigated by the DED which forces the engines to play a greater number of variations. This paper describes a further test of the DED using a new set of openings. The motivation for this study is that conventional methods of evaluating chess openings are inadequate. Grandmaster opinions are subjective and inconsistent, while the win-loss-draw statistics in opening book databases are field data that were not taken under controlled conditions and are therefore confounded by intervening variables that have a greater effect on game outcomes than the opening (Munshi, A Method for Comparing Chess Openings, 2014). As a result, there are conflicting opinions on the merit of the different lines in the opening book and these opinions have engendered ongoing debates that have no satisfactory conclusion. It is proposed that an objective method for evaluating openings will settle these issues and help to refine the opening book.