Expected Villa: Analyzing Kodjia’s return to the scoresheet

Welcome to Expected Villa (xV), a post-match column on the stats behind Villa’s results.

One of the reasons I really love looking at football through a mathematical lens is that it allows us to sidestep our conventional, results-based bias to take a look at how the match actually played out. Did it play out exactly how we saw? Which moments are emphasized?

Aston Villa made us sweat Saturday, but hung on for a 1-0 win over bottom side Bolton Wanderers. It was a fourth consecutive league win. This is neat.

Jonathan Kodjia is back on the scoresheet and Villa kept a clean sheet. Those two things mean… a win! Today, though, we spend a lot of time analyzing one moment: the big one.

There’s a lot to unpack from Villa’s goal

If you’re going to give a stats nerd a perfect goal, the lone one Saturday isn’t too far from it — this sequence is absolutely beautiful from a “let’s have fun with xG” standpoint:

• Jonathan Kodjia and Albert Adomah are 2-on-1 with the keeper, but Kodjia takes the shot himself instead of passing to Adomah, who has a better chance
• The goalkeeper saves Kodjia’s effort, sending it behind for a corner kick
• Kodjia wins, then converts, a penalty from the ensuing corner

We’ll start with the non-pass, which was a big talking point:

Kodjia has a good chance here, one-on-one with the keeper, a chance you’d back him to take most of the time. Adomah, however, has the much better chance — if Kodjia squares properly, Adomah will simply have to tap the ball into the back of the net for the goal, as neither the keeper nor trailing defender will be able to get back in position in time to prevent the goal. Generally speaking, Kodjia has absolutely made the wrong decision here: Squaring for Adomah is both (1) a higher xG chance and (2) doesn’t require a particularly good ball, so this would be the dominant strategy.

Granted, in Kodjia’s defence, there are arguments for why he should take this shot. If his pass for Adomah is poor, Villa get no chance to score out of what is a very good situation. If Adomah has somehow drifted offside, Villa get no chance to score out of what is a very good situation. If the keeper anticipates the pass and Adomah’s finish is a little poor, Villa don’t score out of what is a very good situation.

But as it happened, Kodjia’s execution was poor on the shot, and Villa didn’t score out of what was a very good situation. Well, until…

Kodjia’s shot is deflected behind for a corner, from which Kodjia wins, and subsequently converts, a spot kick to put Villa up 1-0.

Firstly, this sequence of events does not vindicate Kodjia for a poor decision earlier, mainly because scoring a goal off a corner is generally a crapshoot — it happens far less often than you’d perhaps think — and a team should always consider themselves a little fortunate when a chance comes their way off a corner.

However, as much blame as Kodjia deserves for the decision not to square to Adomah, he deserves a lot of credit for the manner in which he won the penalty. Too often, we think of penalties as being exclusively because of defender error, and not because of attacker skill. This was more a case of the latter, for me, as the former, and is not significantly different in analysis than what happened just earlier, where good play put Villa in on the keeper 2-on-1.

Finally, though, it allows me to bring in a quirk of xG math: it sometimes doesn’t add up the way it should. Experimental 361 said Villa were the clear better side, with 1.7 xG for and 0.7 against, but if you get a chance, take a look at that xG timeline. Most xG systems (if they account for penalties at all*) will value a spot kick at around 0.74 xG, and e361’s from the Villa match Saturday clearly does.

But that penalty is only possible because Kodjia misses the good, but not great, chance that came before it. Let’s say Kodjia’s probability of scoring there is 30 percent, denoting an xG of 0.30 — if you treat the two as independent events, as most xG models will, Villa’s total will come to 1.04 xG. We know that situation isn’t possible. There are a number of different “fixes” that can be done, but none of them are perfect. This is still an area where analytics can struggle a little.

The next five matches are much tougher

Villa have done well recently. They’ve also played three of the four worst teams in the Championship, plus Nottingham Forest, who are probably a lower-half side at the end of the day.

That won’t be the case over the next five-match run. Villa visit Wolves on 14 October to start the month, then host Fulham the next weekend. A crosstown trip to a poor Birmingham City side follows, but derbies are always tough. The run finishes with a trip to Preston North End on 1 November, and a visit from Sheffield Wednesday that Saturday, where Villa will wrap up three matches in seven days.

If Villa are still fighting around the right end of the table, it will show great progress — and will mean the club are in a great position headed toward the festive season. Wolves and Preston are two of the six teams ahead of VIlla right now, Fulham and Wednesday are really good sides lingering just back of us, and Blues is a derby. Three wins would be a fantastic result.

Aston Villa are finally settling into a consistent XI

Steve Bruce has started the same 11 guys over the last four league matches, and this is a great thing (Neil Taylor’s stupid red card aside). Villa spent most of last season cycling through different combinations with no real idea of what the best team was — the most-used XI got just 158 minutes together — as only seven guys played in a majority of matches.

If there was one thing that united most of the division’s top teams, it might have been a consistent squad selection. Ten players contested at least half the season’s minutes from Brighton, Fulham and Huddersfield, while 12 did for each of Newcastle, Reading and Sheffield Wednesday.

Only eight players have seen the pitch for more than 495 minutes so far this year, but it seems realistic to expect that both Robert Snodgrass (470) and Adomah (466) will both cross that threshold sooner rather than later (and it could happen as early as that Wolves match for each of them). Jonathan Kodjia, eventually, will do so as well.