One league divided the teams into three tiers according to the skill level of players , and there were no age restrictions for players within these three tiers .
Coeducational hockey teams and loose affiliations of individual teams that share ice time were not considered for this study .
One league divided the teams into three tiers according to the skill level of players , and there were no age restrictions for players within these three tiers .
Coeducational hockey teams and loose affiliations of individual teams that share ice time were not considered for this study .