I would suspect it has to with contact and commitment to the relationship prior to the kid committing. Calls, texts...finding reasons to check in and just overall attaboys when son has a good game. You know it when you see it and you know when they fake it. My son was a late prospect ( if you would cal him that, meaning he came on the recruiting radar later than normal) and had a whale of a game playing up vs 18U kids and almost struck everybody out (kidding but had alot of Ks) and there were tons of RCs there. He got everything from "Tell your parents they won't have to pay a dime", to "Come take a visit and you won't want to leave". In the end, most had barriers related to how much they could offer and the winning coach who landed son just flat out impressed him and communicated his desire to have him in his program (For TPM, this was #7).
Hope this helps.