Hi all, I am experimenting at the moment on how various replacement strategies affect gp evolution. In particular I am examining the so-popular generational and steady state approaches which are already implemented in ECJ. Apart from that Ive implemented two other approaches. Briefly, in the intermediate approach, a X% of the population is produced (0<X<=90) , then the rest of percentage is filled with members from the old population. In the greater-than-generational approach, similarly, a X% (200<X<600) is combined with the old population, to allow the fittest part of them as the new population.There is no multithreading , nor elitism. Even though the populations seem to be generated and sorted as expected, I couldnt figure out expected success rates. Anyone that might want to have a look, I attached the two breeders in this message. Thanks v. much. Best Regards, Marios.