1. Kid would probably make new friends not unlike travel and get better playing with older kids. 2. Not a significant advantage over the fall winter of his year but a huge advantage over the summer fall winter kids of the grade year. He could be a 1 yr 4 months older. On a combo even greater 2 years 4 months. Example 1/2 team 6 year old vs 8 and a half year old. Worse 5/6 10 yearold vs a 12 and half year old who hit puberty. Would you want to have your kid play? 3. The holdback is not trading off anything, the parent is creating an artificial advantage academically for child and also using it to create an advantage in athletics also. Which is really pronounced in lacrosse because unlike other sports its not being age regulated. 4. No. All parents do what they think is best for their child, if something a parent does for their child adversely affects another parents child , isn't it up to the us as parents to stick up for their child especially when some parents have a total disregard for another childrens well being or are being taken advantage of. Sometimes a kid is just better or bigger than the others. As a coach I have seen kids that I thought were prodigies or really physically gifted then I find out they are holdbacks or double holdbacks. Man, that 10 year old plays like a 13 year old. Coach, thats because he is 13.