I said about 12-18 months ago I felt Calvert Lewin could channel some of the aspects of both a prime Duncan Ferguson and Marcus Bent (although substitute in there Radnziski or Andy Johnson as appropriate). He had a unique combination of being quite quick and also having an enormous leap. Where he struggled was putting it all together. You'd see him winning headers on the right wing against a left back, but never really putting himself between the posts to win headers.
I pointed out to improve he would need to do 2 things. Firstly have better movement, and make himself much easier to put in behind from midfield. Secondly to ensure that he is arriving in the box at the right moment to attack the ball at it's highest point when it's at the centre of the goal.
In all honesty there have been enormous improvements in those things over the last 6 months or so. Enormous strides. I'm not saying he's the finished article but he's a long way there. His movement is much better and he's regularly winning headers in the right areas now. The one at Arsenal that went the other side of the post, was akin to a prime Ferguson. Nobody could get near him.
What he's not is a natural goalscorer. While I think much of this is an inherent skill I do think it can be improved. I think he's improved his finishing but there is still a little way to go. We are at the point where quite a small improvement is going to make quite a big difference. Most games now he has 2-3-4 chances. In all honesty most defences can't handle him. I'd also like to see him use his body better when running with the ball. I think of the one at Anfield with Van Dijk, if he cuts across Van Dijk it will be a red card and a penalty. He's unlucky not to have a penalty, but he needs to make it clearer.
What I will say with him though, is of all the younger players we've had is he has got better and better with each season. I think he will continue to improve. I also think Ancelotti who has worked with (and improved Inzaghi, Ronaldo, Levandovski etc) will pass on a lot of knowledge to him.
I don't doubt there are weaknesses to his game. However I'm very happy to be talking about weaknesses in the game of a lad who's getting 18-20 league goals a season I am quite comfortable with. Lukaku had lots of weaknesses too, but we'd all have him back in a heartbeat I'd imagine.