From this years NSW JRU State Champ Rules:
3. PLAYER QUALIFICATION
i A player is qualified to compete in the JSC if:
a. He/She has played in 2013 at least 4 club competition matches for a club or country town, within the Sydney District/ Country Zone he/she is seeking to play for (U10s to U15s).
b. In U16 age group, he has played at least 4 club competition matches for a junior club or country town within the Sydney District/ Country Zone he/she is seeking to play for, in 2012 or 2013.
c. In U17 age group, he has played at least 4 club competition matches for a junior club or country town within the Sydney District/ Country Zone he/she is seeking to play for, in 2012 or 2013 .
ii Each participant in the JSC must be a registered club player and must have completed the requirements of ARU registration in 2013 with a club, country town, Sydney District or Country Zone association affiliated with NSWJRU. (Interstate competitiors must be registered under the ARU registration system.)
So the eligibility loophole that is exploited is that for Under 16's, provided the boy played at least 4 games in 2013 (U16) or 2012 (U15), and they are registered with a village club in the ARU system in 2013, then they qualify to participate in State Champs.
In 2012, if there is a bye, washout or forfeit (or combinations of the above) then the player is deemed to have "played" the game. In 2012 if you can manage 1 Bye, 2 washouts and a forfeit against your team, then all your Ghost player needs to do to play State Champs is to be registered on Buddha in 2013 and 2013 with Club X, and they are OK for State Champs without physically playing one game for Sydney Juniors in the 18 months prior to the U16 State Champs.
Fairly simple loophole to rort for the U16's.
For U17 State Champs, provided your "team" in U16's (2012) had a draw with a bye or a forfeit or two in it, and you are also home and hosed as a Ghost player for U17 State champs in 2013. Slightly more tricky to exploit the loophole for the U17's, but not impossible. This is why the number and quality of players at U17 JSC seems to drop off significantly from the U16's.
These rules have been in vogue for many years, and there is no reason to believe that they will change in the immediate future.