No, a system that picks two horses in the same race will have exactly the same outcome for a systems that picks two horses, but in entirely different races ..... provided that the filters are exactly the same. You could have the systme pick 4 horses in the same race, and that very same systme might pick 4 horses in 4 separate races. It wont alter the S/R, the S/R will be what is is regardless of multiple runners or not.