We want to see equal opportunities for everyone, especially at a younger age. At these young ages, it is necessary that kids learn the values of working with others and developing social skills, to learn how to cooperate and to work as a team. We want to make better human beings, not 9 more selfish players on a field. Girls and boys should stop competing together at the age of ten. The reason we chose the age of ten was because boys and girls mature at different ages.
Some girls start maturing as young as eleven and boys around the age of thirteen.
Stopping co-ed sports by the age of ten takes care of any girls who start maturing earlier than average. A study by Youth Sports showed that boys and girls, prior to puberty, can compete against each other on the same teams, provided they have all had the same skill training. The physical differences in size and strength manifest themselves at about eleven years in females and thirteen years in males. The article also mentions that after these ages, males, in general, start getting taller, heavier, and show greater speed, strength, power, and overall size. Letting the kids' play with and against each other when they are going through the early stages of maturity is a bad idea.