I think Anhyzer for sure. It is easy to flip it too much or not give it enough spin and then it fades back. Fortunately for me, I am Lefty, so I HAD to master it (Many courses I have played over the yrs and the 1 (H.B. CA) I learned on were very Righty biased). But, most RhBh throwers struggle with it.
Also rollers can take a minute to figure out. It is very subjective to the surface you are rolling on and how hard it hits the surface, how much spin you put on it, how long it is in the air vs. on the ground..... etc, etc
Right now, for me personally, throwing RhBh for distance would be my only "difficult" throw to master (although I am getting pretty good). I don't need to learn it for distance, cuz I gotta nice anhyzer. But it has been $$$ for short right to left hooks and approaches. RhBh putting i need to work on, but I don't really ever have to putt that way