Redshift evolution of differential merger rates of BBH merger GW progenitor events in four different boxes of the MTNG simulations: MTNG46, MTNG92, MTNG185, and MTNG740 (from left to right). Top: Distributions displayed as a function of the mass of the primary black hole (m₁) of the merging compact binary systems. Bottom: Distributions in terms of mass ratio q ≡ m₂/m₁. Merger rates are normalized relative to the comoving volume of each simulation and to the time span (in gigayears) covered by the redshift intervals reported in the legend.