Two candidates come to mind for me
Demetrious Johnson
Pros:Since 2010 hes gone 18-1-1, currently riding a 12 fight win streak he is also currently tied for most consecutive Title defenses(10).
Cons:Strength of schedule, last few years i feel as though hes getting fighters before their actually ready because of how thin the top ten is.never the less its no easy task what hes been able to accomplish.I feel where only witnessing the tip of the ice berg for the talented Flyweight Division.
Connor McGregor
Pros:Since 2010 hes gone 17-2,14 of those wins were by TKO/KO.Two division champ in two different organizations.(UFC/Cage Warriors FW/LW Champion).
Cons:Unlike MM defending his titles seems to have become a problem for the enigmatic McGregor.If he can come back and string together a few title defenses he should be right in the running come 2020.
Dark Horses
Dominick Cruz-The Greatest Batamweight to date, if he can recapture his title and defend it without interruption he is right in the mix.
Max Holloway-Currently on a 11 fight win streak since his loss to Connor Mcgregor this guy has all the makings of a long term champion at 145.
Stipe Miocic-Anyone who can stay afloat in the UFC HW Division is worth taking note of.If he can stay on top till 2020 or close to it he'll be right in the conversation.
Sorry for the long read
Demetrious Johnson
Pros:Since 2010 hes gone 18-1-1, currently riding a 12 fight win streak he is also currently tied for most consecutive Title defenses(10).
Cons:Strength of schedule, last few years i feel as though hes getting fighters before their actually ready because of how thin the top ten is.never the less its no easy task what hes been able to accomplish.I feel where only witnessing the tip of the ice berg for the talented Flyweight Division.
Connor McGregor
Pros:Since 2010 hes gone 17-2,14 of those wins were by TKO/KO.Two division champ in two different organizations.(UFC/Cage Warriors FW/LW Champion).
Cons:Unlike MM defending his titles seems to have become a problem for the enigmatic McGregor.If he can come back and string together a few title defenses he should be right in the running come 2020.
Dark Horses
Dominick Cruz-The Greatest Batamweight to date, if he can recapture his title and defend it without interruption he is right in the mix.
Max Holloway-Currently on a 11 fight win streak since his loss to Connor Mcgregor this guy has all the makings of a long term champion at 145.
Stipe Miocic-Anyone who can stay afloat in the UFC HW Division is worth taking note of.If he can stay on top till 2020 or close to it he'll be right in the conversation.
Sorry for the long read