This is a hard question and i think unfair to many who have really made big steps in a short time. Ota seems more assured but was still already a top player i guess. Sterling and Sane have got more awareness and solid idea what they need to do.
I do think non of the other lads would complain if Stones got the bluemoon most improved player trophy. He was very good but is now playing the standard that sees a player firmly labled as "world class".