It was a very good year but not great. 3 out 4 Slam finals reached, 1 Slam win, Mimai and Canada won, now if he finished the season as #1 I'd be very satisfield
Yes this is the big difference. And also just luck. It went his way last year in close matches; this year not so much, apart from the A.O.
So you're basically saying that all his Slam wins were luck