The most complete look at the current state of the HGP rule and the exceptions to the rule that have been granting. Yes, Brent Richards was an exception, but there have been a few others.
There's also a nugget that now seems to incentivize a club operating an amateur PDL team in order to main their connections to former U18 players who are then at colleges. The clarity added in this story includes quotes from Todd Durbin of MLS but still reinforces that MLS granted the Timbers an exception that the rest of the league does not receive.
