Looks like NW3v to me. Hop on the big three as the guy before me told you to! If you've only gone that far in 4 years, it means your male pattern baldness isn't very aggressive right now and you still have a lot of hair to work with, so minor regrowth in the temple area, filling some of the cowlick area in the back, on top of maintenance would do that head of hair great things. Regrowth likely to be achieved on minoxidil and maintenance/halting of the balding progress on Finasteride. You have only had hair loss for 4 years so the follicles should be still alive and kicking, more or less.