A very good question!
Years ago when I was involved with airline training I tried to write down the definition of a good Captain. I found the task almost impossible until I started to define a bad Captain and then "invert" my findings!
For example, a "bad" Captain would turn up for work late and unprepared. So a "good" Captain would be on time (or even early) and prepared in every way. You get the idea?
Also whilst it is important that a "good" Captain follows SOPs, there is a difference, I feel, between doing "things right" and doing "the right thing".