Stats without any context. I've linked all 12 goals we've conceded in his 13 starts for us this season below.
1 : Mata gives the ball away, Lindelof is turned inside out and lets his man shoot. Smalling? Doesnt do a lot wrong, he's tracking his man at the back. If he was the best defender in the world he might have reacted after the saved Ince shot and launched himself in the way of the second shot and blocked or headed it clear but I'm not sure any current CB around the world would have got it right 10 times out of 10 and stopped the shot.
2: Lindelof can't defend a high launched ball from the keeper, a bad header back to his own keeper leads to a great chance. Smalling? Tries his best to get back and block the shot on the line but just cant make it. Nothing he can really do here, other than perhaps being in charge of dealing with every high ball and doing 2 CB jobs at once.
3 : Smalling tracks the run from midfield because for some reason Jones has planted himself yet allowed a great cross to come in. Ashley Young hasnt gone back to his box to help defend so Smalling has covered a large amount of space to make up for the defenders on this side being out of position. Bailly hasn't reacted to the shift in team shape and come across to help out. Neither has Valencia. This is a cock up from the entire defence and the closest to doing the right thing is Chris Smalling.
4 : Ashley Young pushes up to pressure the man on the ball and a fast double team movement takes both he and Matic out of the game. Smalling tries to cover, puts some pressure on the winger so he cant get a quality ball in. Perhaps he could have managed a block, perhaps not. But the ball in was poor and Lindelof slips over when it would have been easy to deal with otherwise. Easy finish and not much any of the other defenders can do after he does that.
5 : The Rojo Special - Gets turned and then dives in with little chance to win the ball and catches the player. Got away with a bunch of these last season, this time its punished. Smalling is not a surgeon and won't be performing any brain transplants in his lifetime so there's nothing he could do here.
6 : Pogba and Ander are 5-10 yards apart leaving plenty of space in the middle and on the other side. Lingard is closest to the player who ends up having the chance and hasnt tracked him properly which could have made up for the midfield mistake. Smalling and Rojo are close to each other at the start, but an attacker makes moves further from Smalling so he puts himself in a position to deal with any crosses towards him. Meanwhile Rojo doesnt at any point look and notice this and in fact moves towards the player that Ander has tracked back to cover. Theres absolutely no need for Rojo to have moved and in fact the final chance falls to the player about 5 yards behind where Rojo started. So if he had just moved slightly back with the play as the attack progressed instead of running down towards the player already tracked then he'd have been in the perfect position to easily cut out the cross.
At most we could say that once Rojo moves when he doesnt need to, Smalling could possibly have seen that and stopped tracking his man and moved closer to Rojo and not leave as much space undefended. That would have put Smalling in a good position to pressure and perhaps block the shot if lucky. At the same time that would have left the players at the back post unmarked for the cross because even though we have 2 other players towards the back, meaning we have 3 vs 2 there - only Smalling moves in a way that would see him beat his man to the ball.
Valencia and Lindelof may possibly have done more to cover if Smalling had moved over to cover the space Rojo left behind without a reason. We'll never know if thats the case, but we can see they dont look convincing in where they place themselves when the cross comes in. So again if Chris Smalling was the best CB in the world he might have moved to cover Rojo's error and possibly distracted or blocked the shot, which is more like he did in the previous Chelsea example.
Again its a defence-wide lack of coordination and Smalling does the best defensive work of the backline, but at the same time its entirely possible that he could have done a little more. Compared to the other defenders who should have done a lot more.
7 : Lindelof, a bit like Jones earlier, just stands there and allows his opponent to play a fantastic ball into a dangerous area. It goes way over Smalling's head, nothing he can do about that. Its over Rojo too but the man who runs in behind him, who Rojo stops to point at saying he's offside maybe, hopefully, miss controls the ball backwards to a teammate who puts it in. And the 2nd man, who was also closest to Rojo could have been covered if he was moving to react to the pass instead of hoping the referees assistant would bail him out.
8 : Lukaku does a poor job with his challenge and the ball drops to a City player who turns it in.
Lingard and Matic both get sucked under the initial cross and take themselves out of play. Lingard at least leaps to try and challenge for the ball though, Matic on the other hand starts in the perfect position to have dealt with Lukaku's bad touch back. For some reason known only to Nemanja Matic, he moves out of the 6 yard box, closer to the corner and under the ball. I gather he was there for a reason at the start, to defend the 6 yard box but he deserted it and decided to have a break from the game for some reason instead.
9 : Lukaku swings his right boot at a cross and it bounces back off a teammate to a City player who turns it in.
10 : Corner comes in Rojo doesnt deal with it, doesnt react and it bounces off his knee towards the middle of the 6 yard box, is flat footed and again doesnt react and it falls to an opponent inside the box. Rashford is there to try and help out but doesnt manage anything either. Smalling tracked his man, but his man pulled wide and Smalling went with him so he wasn't defending the middle of the goal. We had 6 other players in the 6 yard box, at least 2 of them (Mainly Rojo but also Rashford) could have done a lot more than they did.
So there you go, the first 10 goals and Chris Smalling is
perhaps guilty of 1 thing - Not covering for Rojo's mistaken positioning in goal 6. And thats being very slightly harsh because he was still doing a good job defending the situation that he is taking care of but if he had moved over like he did against Chelsea on this occasion it may have bailed us out.