I generally agree with Pabaseball on this, but there are cases where a PG can have some value, I think. Certainly when I look at many of the top recruits in the 2020 class I see a lot of kids who are a full calendar year older than my RHP son, so they have the benefit of another year of physical development they gained by either starting school late or maybe being held back at some point.
For my son, the PG question is still an open one. I absolutely don't want to make it another year of high school, or to indulge a college fantasy that isn't real. But my son is coming back from nearly a year off from testicular cancer (I wrote on this board about him a while back). He's doing great now, sitting 85-86 and running up to 88 sometimes. He's got a little interest from some small D1s, but he may not be able to log enough innings to really return to form and get the attention of the schools he's most interested in before the recruiting window on 2020 closes.
So, I'd love to hear some ideas about good PG programs for baseball players.
Age doesn't matter once in HS. A player from our summer team was drafted. He didn't turn 17 until December. Coaches look at projection - what a player can become if they train him. All these 15 year olds commit because coaches look at where they can be in 4/5 years. A kid who doesn't turn 17 until September of his senior year is still going to have trouble getting offers the following summer as the schools that have already seen him have decided they're not interested and the new schools would presumably be in the lower level D3/JUCO range. Not that there is anything wrong with either but no sense in spending another 50k in tuition to do so.
Is there an advantage to starting a kid late or holding back in MS? Absolutely, that is also different than extending HS by another year once you're already there. HS is HS. College sports are just a bonus. 95% of HS players will attend college as regular students. If it doesn't happen it doesn't happen. You can't force a kid to be better at baseball or force schools to be interested.
I have no problem with PG year for health reasons, academic purposes, maturity issues, draft purposes, or extenuating family circumstances. I just don't think because a kid is 17 as a senior and he has a few 19 year olds in his class that he should be staying back to fill a college fantasy that most likely won't happen.
Sounds like your son is doing well, good luck to him moving forward. 86+ will definitely attract a number of schools.