ICCA Journal, Volume 22:  Number 3  (September 1999)

TABLE OF CONTENTS

Editorial:                                                                                          
    Many Changes (H.J. van den Herik) .......................................................... 121
Contributions:                                                                                      
    Adaptive Null-Move Pruning (E.A. Heinz) .................................................... 123
    Efficient Approximation of Backgammon Race Equities (M. Buro) .............................. 133
Review:                                                                                             
    A Transference of Bones (D. Hartmann) ...................................................... 143
Reports:                                                                                            
    Thirteen Years On (D.N.L. Levy) ............................................................ 146
    Millennium's End (T.A. Marsland) ........................................................... 147
    The 9th World Computer-Chess Championship .................................................. 149
        The Tournament (M. Feist) .............................................................. 149
        The Search-Engine Features of the Programs (D.F. Beal) ................................. 160
        The Man-Machine Contest (M. Feist) ..................................................... 165
    Report on the Advances in Computer Chess 9 Conference (Y. Bjoernsson) ...................... 167
    Minutes of the ICCA Triennial Meeting (D.F. Beal) .......................................... 171
    The Advanced Chess Match between Anand and Karpov (F. Friedel) ............................. 172
    Report on the Machine-Learning in Game-Playing Workshop (J. Fuernkranz and M. Kubat) ....... 178
    Report on the 9th CSA World Computer-Shogi Championship (M. Sakuta and H. Iida) ............ 180
    Report on The First International Shogi Forum (M. Sakuta and H. Iida) ...................... 183
    The ChessBase Best-Publication Award (The Board of ICCA) ................................... 185
    The ICCA Journal Award 1999 (The Board of ICCA) ............................................ 186
        Ernst Heinz: A Scientific Biography .................................................... 186
    Calendar of Computer-Games Events in 1999 and 2000 ......................................... 186
    The Swedish Rating List (T. Karlsson) ...................................................... 187
Correspondence:                                                                                     
    The ``Brains of Earth Challenge'' (J. Nunn and F. Friedel) ................................. 188
    Correction on Dap Hartmann's Review (I. Althoefer) ......................................... 190
        Reaction of the Reviewer (D. Hartmann) ................................................. 191

ABSTRACTS OF SCIENTIFIC ARTICLES

Adaptive Null-Move Pruning

Ernst A. Heinz

[22(3):123-132]   General wisdom deems strong computer-chess programs to be ``brute-force searchers'' that explore game trees as exhaustively as possible within the given time limits. We review the results of the latest World Computer-Chess Championships and show how grossly wrong this notion actually is. The typical brute-force searchers lost their dominance of the field around 1990 when the null move became popular in microcomputer practice. Today, nearly all world-class chess programs apply various selective forward-pruning schemes with overwhelming success.

To this end, we extend standard null-move pruning by a variable depth reduction and introduce what we call adaptive null-move pruning. Quantitative experiments with our chess program DARKTHOUGHT show that adaptive null-move pruning adds a new member to the collection of successful forward-pruning techniques in computer chess. It preserves the tactical strength of DARKTHOUGHT while reducing its search effort by 10 to 30 percent on average in comparison with standard null-move pruning at search depths of 8 to 12 plies. Moreover, adaptive null-move pruning is easy to implement and scales nicely with progressing search depth.

Efficient Approximation of Backgammon Race Equities

Michael Buro

[22(3):133-142]   This article presents efficient equity approximations for backgammon races based on statistical analyses. In conjunction with a 1-ply search the constructed evaluation functions allow a program to play short races almost perfectly with regard to checker-play as well as doubling cube handling. Moreover, the evaluation can naturally be extended to long races without losing much accuracy.

EDITORIAL

Many Changes

H. Jaap van den Herik

[22(3):121-122]   This issue of the ICCA Journal is unable to record properly all the changes the computer-chess world faced in the summer months of 1999. Of course, we did our utmost, and so we are able to offer our readers a long list of changes adequately reported in the pages to follow. Below we briefly deal with them in an order which gives priority to human beings above scientific findings.

First, the Editors would like to congratulate Stefan Meyer-Kahlen on winning the title World Champion among computer-chess programs for the period 1999 to 2002. His program SHREDDER achieved a deserved first place at the WCCC'99 in Paderborn, after an exciting play-off against FERRET (Bruce Moreland). SHREDDER took over the title from FRITZ (Frans Morsch, Cock de Gorter, and Mathias Feist).

Second, after thirteen years of services our President Tony Marsland has stepped down. The overview of the activities and tournaments under his Presidentship is impressive. We thank him for his enthusiasm, his scientific contributions, and his guidance. Much wisdom was necessary to keep the ICCA going on the right track.

Third, the conference Advances in Computer Chess 9 was an overwhelming success. This series of conferences has attracted the attention of game-playing researchers from all over the world. The result is that those researchers submitted papers on many games different from chess. As a consequence the idea of changing the name from Advances in Computer Chess to Advances in Computer Games has been almost generally welcomed. Fourth, the developments mentioned above had not escaped the attention of the new ICCA Board. Therefore, they suggested in the Triennial Meeting to broaden the scope of the ICCA Journal officially by encouraging the Editor to solicit contributions which are not chess-specific, but games-oriented. The result of this change in policy has already been incorporated in this issue. (See also below.)

Fifth, the ChessBase organisation has expressed the willingness to cooperate more closely with the ICCA. In addition to their articles (see the article by Frederic Friedel and also the Correspondence section), they have contributed a CD ROM for our readership containing opinions bridging the gap between human Grandmasters and top programs.

Sixth, the ChessBase organisation has offered to continue the Mephisto/Novag Award. For 1999 we will again have an Award, of course now called the ChessBase Best-Publication Award, which enables the ICCA to distinguish a researcher or a group of researchers for their excellence.

Seventh, the ICCA Board has been enlarged by the position of an ``active programmers'' representative. This position is now filled by Martin Zentner. The ICCA expects many ideas and activities from him, which will be communicated to our readers in the Journal.

Eighth, the subscription fee has been settled for international use as US-$ 40 (as was) and Euro 40. (See the minutes of the Triennial Meeting.)

Ninth, the ICCA Board has decided (September 11, 1999) to combine ideas of the uniform-platform tournament and the annual World Microcomputer-Chess Championship (WMCC), by organising a World PC Computer-Chess Championship 2000 in London on a uniform platform. For details, see the Presidential Address.

Tenth, the Editorial Board is proud to have been able to report since 1983 a scientific breakthrough in each issue; sometimes a small one, at other times a larger one. The last two years we were fortunate to publish many outstanding contributions by Ernst Heinz. Again, his Adaptive Null-Move Pruning enhances our understanding of the intricacies of game-tree search. No change in his series, but an increase in our knowledge.

After the many changes mentioned above, your Editor feels he is still running to keep up with the many changes in the computer-games field. Let us hope that the 21st century will continue the current slope.