Method for identifying combination(s) of at least three non-human individuals within a breeding population using a genotype/phenotype relationship model that estimates for a given genotype of an individual what the quantitative contribution is of the allele substitution effects of a plurality of loci on the at least one phenotypic trait of interest, wherein the combinations have for at least one phenotypic trait of interest a higher Combined Genome-Wide Estimated Breeding Value in the offspring for said at least one phenotypic trait of interest, as compared to at least 70% of the other combinations of at least three individuals within said population, wherein the method comprises: a) genotyping each individual within a population by using - molecular marker techniques; - sequence-based genotyping by sequencing; or - whole genome sequencing, wherein the genotypic data collected in this step relates to the plurality of loci of the genotype/phenotype relationship model; b) calculating for each individual within the population the allele substitution effect for each allele of said plurality of loci by using the genotype/phenotype relationship model, and correcting for recombination probabilities with flanking loci, preferably wherein for an allele with a positive allele substitution effect the probability is taken into account that said allele is transmitted to the offspring, and for an allele with a negative allele substitution effect the probability is taken into account that said allele is not transmitted to the offspring; c) determining the Combined Genome-Wide Estimated Breeding Value in the putative offspring for the at least one phenotypic trait of interest for each combination of at least three individuals within the population by calculating for each combination of at least three individuals for each locus of said plurality of loci in the offspring the highest combination of allele substitution effects using the calculated and corrected allele substitution effects of the individuals calculated in step b); and, d) identifying the combination(s) of at least three individuals within the population that provide for said at least one phenotypic trait of interest Combined Genome-Wide Estimated Breeding Values in the offspring that are higher than at least 70% of the Combined Genome-Wide Estimated Breeding Values in the offspring of other combinations of at least three individuals within the breeding population. a) genotyping each individual within a population by using - molecular marker techniques; - sequence-based genotyping by sequencing; or - whole genome sequencing, wherein the genotypic data collected in this step relates to the plurality of loci of the genotype/phenotype relationship model; - molecular marker techniques; - sequence-based genotyping by sequencing; or - whole genome sequencing, b) calculating for each individual within the population the allele substitution effect for each allele of said plurality of loci by using the genotype/phenotype relationship model, and correcting for recombination probabilities with flanking loci, preferably wherein for an allele with a positive allele substitution effect the probability is taken into account that said allele is transmitted to the offspring, and for an allele with a negative allele substitution effect the probability is taken into account that said allele is not transmitted to the offspring; c) determining the Combined Genome-Wide Estimated Breeding Value in the putative offspring for the at least one phenotypic trait of interest for each combination of at least three individuals within the population by calculating for each combination of at least three individuals for each locus of said plurality of loci in the offspring the highest combination of allele substitution effects using the calculated and corrected allele substitution effects of the individuals calculated in step b); and, d) identifying the combination(s) of at least three individuals within the population that provide for said at least one phenotypic trait of interest Combined Genome-Wide Estimated Breeding Values in the offspring that are higher than at least 70% of the Combined Genome-Wide Estimated Breeding Values in the offspring of other combinations of at least three individuals within the breeding population.