Information in Transposition Tables
Dennis M. Breuker, JOS W. H. M. UITERWIJK, H.J. van den Herik · 2007
Due to transpositions a search tree can be considered as a search graph. The transpositions are stored with information about previous searches in a transposition table. Although the use of transposition tables is standard practice, it is still an open question how large the overall reduction is and especially which information has the largest impact on the reduction. The paper describes an experiment to distinguish between the reduction given the best move is stored or the value of the best move is stored. A second experiment compares storing the bound values for minimal-window search with storing the true values. It transpires that the highest reduction comes from re-using bounds because they adequately generate cutoffs. Since we know that from a certain transposition-table size not much is to be gained from doubling the number of entries, it might be useful to store additional information to see whether this leads to a better result. Our first experiments on the use of more informat...