I agree with that also. If I am seeing correctly dont most grad. year tournaments/leagues also have a age range for the teams? Or do they say all ages? Also if its 2019 team they are 8th graders if they are hold back they are 1 year older which makes a 2 year age window. So if you have U15 its 8th and 9th graders so its a 2 year age window. I just see it as a shift of the 2 year age window.
