Mixed size tournament selection

Abstract

 In genetic algorithms, tournament schemes are often applied as selection operators. The advantage is simplicity and efficiency. On the other hand, major deficiencies related to tournament selection are the coarse scaling of the selection pressure and the poor sampling accuracy. We introduce a new variant of tournament selection which provides an adjustable probability distribution, a fine-tuning facility for the selection pressure and an improved sampling accuracy at the cost of a minimal increase of the complexity and with almost no loss of efficiency.