A lot of fans, as well as McGregor himself are calling for his move to Lightweight, which is his natural weight-class. Many fans are saying he would dominate and have equal or greater success. I believe his fight with Siver will give us a solid indication of how McGregor will stack up at LW. Siver is a solid guy who had some success, but LW is full of vicious strikers. When facing them, Siver was dismantled by Cerrone and Guillard with absolute ease. If McGregor beats Siver, but struggles with him or fights competitively for most of the bout, will it change your opinion on his eventual move up to LW? Lightweight is a different monster with strikers like Cerrone, Pettis, Barboza, Dos Anjos. Etc. Lets be honest, Poirier would get cremated by any of those guys.