We could ask Collin, As far as I can remember he said that a Baby Koi is not based on size but on age.... up to 3yrs? can even be 70cm, should really then be called a Young Koi Show!!
Does not make sense to me, maybe we should explore a Western Cape unofficial one day Baby Koi Exhibition up to size 4 and get the Dealers to be the judges, as a means to create more interest in the Koi hobby.