When?
Last year, about 3-4, he showed the basics, but didn't stand out. Could have been a passable 4C but there was no reason to rush him.
This fall, about 9, it's not that Vorobyev put up scoring numbers, that was against inferior competition and should be discounted, but his game was so fundamentally sound, the puck seemed to find him, he was always in the right position, used his body, got back on defense, etc. He has subtle little moves when handling the puck that allows him to control the pace of the game. And he has great ice vision, can anticipate where a teammate is going and get him the puck. Not sure what his upside will be, but it'll be fun to watch how far he progresses the next few years. I think he could be a solid 2C down the road.
I saw something similar watching Farabee in the WJ tryouts this summer, while O'Brien was flashier, Farabee was always in the right place on both offense and defense - the guys with the great raw skills catch your eyes at first - but then you realize that the puck seems to consistently find Farabee, and that it's not an accident.
Couts was like that before he was moved to the first line with Giroux, he had the same performance, just wasn't rewarded with the sexy stats, but all the advanced stats loved him because he both maintained puck possession and suppressed opponents' scoring. One aspect of high hockey IQ guys is they anticipate and position so well they use less energy on their shifts and can play a lot of minutes. You see that with Couts.
I think high IQ guys with good but not great skills are the hidden "efficiency" in hockey, they tend to get under drafted and underpaid because they don't jump out at you v sexier players, and tend not to get the media attention until they're in the league for an extended period.
It's obvious that Hextall LOVES these guys and is collecting as many as he can.