My son played up at 10, 11 and 12......then played a second year at 12U so he could do some pitching. Played 13U on a top level team.....then 14U. We tried as much as we could to not play any 15U teams the next year.....tried to play exclusively 16U. I think it worked well for him. He also played "local" where he got to play against his own age every year. He wasn't always the best player on his travel teams....but I really think the experience of playing against kids a year older helped him out a lot. He's got a late April birthday....so in some cases, the kids were almost 2 full years older than him. Never had any issues....even though we played the top tourneys in the Eastern half of the country. If your son's skillset allows him to play up, I would definitely do it.