Mixed size tournament selection

In genetic algorithms, tournamentschemes are often applied as selectionoperators. The advantage are simplicity and efficiency. On the other hand, major deficiencies related to tournament selectionare the coarse scaling of the selectionpressure and the poor sampling accuracy. We introduce a new variant of tournament selectionwhich provides an adjustable probability distribution, a fine-tuningfacility for the selectionpressure and an improved sampling accuracy at the cost of a minimal increase of the complexity and with almost no loss of efficiency.