I must disagree. The opening sequences are key to pente. One who has played several hundred games or more without the opening restriction will NOT know ANY openings WITH the restriction. This is NOT an easy adaptation to make, except maybe for those who are gifted when it comes to board games. Pioneer is the first I have heard who has said the transition is easy, I have heard many complain that the transition was difficult, and that they wished they had not learned to play incorrectly (without the restriction).
(hide) If you want to play a game with an opponent of a similar level, you can define a required BKR range for a new game invitation. Then nobody with a BKR outside this range will be able to see/accept it. (Katechka) (show all tips)