I'm going to go against the grain here and say it can absolutely make a difference. My oldest son, non baseball, ended up in D1 athletics but got a bite from just one school. If he had taken a year, there is little doubt he would have been a state placer or champion given the year progression he made in skill level, physical maturity, and mental maturity. That would have given him more suitors, and provided him with more choices. Not only was he a year younger, but he was a late bloomer physically. So a double whammy. Not saying it's a route one should take, and it all worked out for us, but if I had to do it again with him, I would have given a year between middle school and high school.