Both the ABA and USFL were successful in attracting top talent to compete in their league. Given that, what were differences in the resolutions between the ABA's challenge to the NBA and the USFL's challenge to the NFL and why did those resolutions differ? Were there differences in initial strategies, later strategies, or how the more dominant league handled the challengers? That is, WHY did one league end up being partially successful and the other league not?

Give all questions of answer with explaination step by step in details answer...