chefjeff said:...Locally, players advance from the APA (and City league, Players Club, Metro) to the two other leagues. I've heard that this is the pattern nationwide. Correct me if I'm wrong...
I would bet that is just your area.
The differences in the leagues is their format not the skill of the players. And, low level players have little or not chance in the APA system. What 2 or 3 can beat 6 or 7 in a race of 8 Ball. If the handicaps are accurate then a 2 or 3 will be lucky to ever beat a 5, 6 or 7. If it was 9Ball it might be different. The low level player can luck in the 9 or the good player can miss on the 8 or 9, giving the beginner an opportunity. But no 2 or 3 can negotiate a full table of balls and get their suit off before a 6 or 7.
On the other hand, BCA has a ball counting system where a 2 or 3 or low level handicap doesn't have to win any games to be effective. Just out run the ball count. This gives them an opportunity to be effective league players when they are beginners. If all they have to do is clear 3, 4 or 5 balls (whatever) they have a chance to do that. Much better chance than to clear their suit and make the 8 before a 6 or 7 level handicap.
Factor in the extremely poor handicapping system of the APA and the league is just bad for pool.