I do single matings on the girls I'm not 100% postive on as far as what egg they lay, and do trio matings or more when I do know 100% who lays what. It helps a ton for spacing, and since I know my birds really well, its easy to know who's laying what. I only have 2 splash copper girls, 5 black copper and 10 blue coppers, I only am unsure on 2 BCMs, they are sisters, so lay very similar eggs, so they get single mated, and 3 of the blues I'm not sure on, but otherwise its pretty simple. Same process for the birchens.