20 - Shots by Arsenal
Not counting the own goal, which was counted as a failed pass, Arsenal took 20 shots against Bournemouth. This is important because Arsenal have averaged just 13.3 shots per game in away matches this season. That said, Bournemouth are a bit of a strange team in that they have allowed the 4th most shots per game at home this season. They play an open, attacking, style which Arsenal were able to exploit.
1.68 - Expected goals by Arsenal
One question I got about xG is whether or not Kolasinac's pass for the O.G. counted toward Arsenal's xG. It didn't. The reason for this is simple: Kolasinac's pass didn't connect with a teammate. Expected goals only counts shots by the team in attack. If you wanted to count Lerma's attempted clearance, you'd probably have to look at all clearances and attempted clearances and how many of them scored goals. Needless to say, this would be an extremely low percentage (aka. low xG) and so including it would be almost pointless.
This was Arsenal's 4th highest xG tally this season (in the League) and 0.67 of the total xG came from just the one shot, Aubameyang's goal.
0.65 - Expected goals by Bournemouth
Arsenal kept a "big chance clean sheet" in this match, meaning that they didn't concede a single big chance for Bournemouth. That's just the second time Arsenal have done that this season and explains why Bournemouth's xG is so low.
Bournemouth also had a goal disallowed for offside which would have been a big chance, probably, but we'll never know because it was offside.
9 - Mkhitaryan lost possession 9 times in this match
If I say that Mkhi had a bad match I'll inevitably get someone responding that he's been a failure at Arsenal. That is to say, he's become something of a hate figure at the club.
I suspect this is down to expectations. If you expect him to be equal to Ozil, you're going to be disappointed. He's Ozil's backup and he plays like it. If you expect him to be a guy who will take over matches or play brilliantly every game, you're going to be disappointed.
Mkhitaryan has only had two good matches for Arsenal this season, the 3-2 loss to Chelsea, where he scored and assisted, and the 4-2 win over Vorskla, where he notched two assists. You could also count his goal against Wolves which rescued a point.
I get both the frustration and also why he plays. The frustration is from games like last night. He had 7 shots, but only one on target, with several shots literally hitting the upper deck. He led Arsenal in xGChain with 1.24 but that just means that he was involved in nearly every move that produced a shot and that he was involved in the move that Auba scored. He also had the nine turnovers (and they were mostly very ugly) and he went 20/26 passing in the first half (though he got better in the second half when he was 17/19).
Why Emery plays him is obvious: he brings energy to the defensive end of things. He averages 2 tackles per90 and leads Arsenal with 2.2 blocked passes per90 - he also chips in with 0.6 interceptions per90. When you consider that Ozil's key passes per90 are down to just 1.6 (from open play) and that Mkhitaryan is at 1.5 while Ozil's tackles (0.9 per90), interceptions (0.1), and blocked passes (0.5) are all significantly lower than Mkhi, I think it's obvious why Emery chooses the Armenian over the German.
Mkhitaryan isn't as sparkly as Ozil. He's not a glitzy player, but he's putting in the hard work, helping his team defensively and offensively, that Ozil just doesn't do. That's why he starts.
Mkhi was a makeweight in a deal that Arsenal basically had to do. We needed to get rid of Sanchez because he was a rotten orange hiding in the dressing room. Until Arsenal can get in a younger, more electric, wide player (or if Emery can pull off a Christmas miracle and get Ozil to play both ends of the pitch) I think we will see a lot more of Mkhitaryan. Just like the Mustafi situation, this is a holdover from the Wenger era and it's going to take some time to fix. In the meantime, you might as well get used to him playing.
0.4375 - Sead Kolasinac pass completion rate in the middle third of the pitch against Bournemouth
I can honestly say that in 18 years of watching Arsenal I've never seen a fullback at my club who passed the ball as poorly as Sead Kolasinac. Anything over 1 yard seems a stretch for him and in the middle of the pitch, where he needs to take care of the ball the most, he's often making really dumb passes.
But what's weird is that in the attacking third, he's fine. He was 15/20 in the attacking final third last night and set up two goals. Any player would be ecstatic for that performance!
While Mkhitaryan is putting in a defensive shift, Sead Kolasinac is not. He went 3/4 tackling, in the first half. In the second half his total defensive output was just the 1 interception and 1 ball recovery. No blocks, no tackles, no clearances, no fouls. Incredible. Emery seemed to just stick him up front and let him prowl around looking for goals. If it works it works.
4 - Wins away from home this season
It's not an exaggeration to say that "Arsenal would have lost this fixture last year" because they literally did, 2-1. Arsenal's away form was infamous and they earned just 16 points in 19 away games last season with just 4 away wins. This season Arsenal already have 4 away wins and 13 points.
What's kicking the Gunners on is that Arsenal have already scored 16 goals in 6 away games, where last season they scored 20 in 19 (2.7 goals per game compared to 1.1 goals per game last season).
Where Emery still has work to do is in away defense. Last season, Arsenal conceded 31 goals in 19 matches (1.6 goals allowed per) and this season they have already conceded 10 in 6 (1.7 goals allowed per). At this rate, the Gunners will match last season's away goals against record, which will make winning away games that much more difficult.
Despite the rather poor defensive record, Arsenal are winning these away matches and that's all that matters at this point in "the process".
Sources: whoscored.com, understat.com, my personal database