A rotor blade of a rotor of a wind turbine, and to an associated wind turbine, and to a method for optimizing a wind turbine. Prior to being mounted on the wind turbine, the rotor blade is split at a parting point into an inner blade section and an outer blade section, wherein a longitudinal direction of the rotor blade is defined from the root section to the blade tip, wherein the rotor blade has at least one swirl element, wherein the swirl element has an extent in the longitudinal direction of the rotor blade, wherein a distance between a start, facing toward the root section, and an end, facing toward the rotor blade tip, of the swirl element in the longitudinal direction is referred to as total length, and wherein a distance between the parting point and the outer end of the swirl element is referred to as outer length, wherein a ratio of outer length to total length is less than 0.25.