Delivery Failure

There can be no denying Celtic’s current form is poor compared to previous trophy-laden seasons. I will look at a range of key performance indicators to see where it might be going wrong.

I have plotted each metric per game back to the start of last season (2017/18). I did not include the 2016/17 season because a) I don’t have all the metrics for that season and b) it was a season where Celtic massively outperformed expected goals models and is thus probably an anomaly.

The numbers shown are the trended averages over the period from August 2017 to September 2018. There is therefore some estimation as to the values. It’s the trend that’s important.

Finally, I have included only SPFL matches. Cup matches against the likes of Brechin City and games against Bayern Munich, for example tend, to skew the averages.

First let’s look at Celtic Creativity Metrics.

Celtic – Creativity

It’s a sad sea of red.

Celtic are completing less passes, and are ceding more possession. The most startling drop is in Total Impect. This is important as it is an indicator to the extent Celtic are breaking opposition lines though passing and dribbling. Consequently, Celtic are bypassing fewer opposition defenders. Not surprisingly the number of chances created is down, but not dramatically.

The huge drop in number of passes completed, and the 42% drop in average Total Impect suggests two trends we see with our eyes:

1. Celtic are playing more slowly – they are simply not moving the ball quickly enough thus the number of passes has dropped off;
2. Opposition teams are increasingly reluctant to open up, and are generally defending deeper making it more difficult for Celtic to play through the lines.

Point 1 makes mitigating point 2 more difficult.

Two obvious changes since last season.

1. Armstrong was the primary line breaker in the squad. He is also a player that does everything very quickly. He plays with great purpose and swiftness of deed. That ability to move the ball quickly forward has not been adequately replaced.
2. The loss of Dembele means that Celtic lack the variety of playing more direct passes to the forward areas. Neither Edouard nor Griffiths are as adept as Dembele was at holding up longer lofted passes. Celtic therefore try and play through deeper defences which is harder to do if the opposition cannot be wrong footed with an early more direct pass.

Celtic are more predictable now. And slower.

Celtic – Goal Threat

Another sorry sea of red.

Celtic’s trended average goals per game has fallen off the cliff. That’s a consequence. What do the other metrics tell us about performance?

It is not really due to taking less shots although the number on target has gone down from an average of 8 to 6. Celtic are, broadly, having the same number of shots from inside the box, and have witnessed only a small drop off for in box possessions.

What explains the goal drought is conversion rates. Celtic are having less shots on target, but the On-Target Conversion rate has tanked from a respectable 33% to only 18% – a huge drop off. All Shot Conversion rate is now 7% which is relegation level shooting.

Celtic are playing against deeper lying sides meaning shots are likely to be against more crowded opposition alignments. But there is clearly a form, confidence, luck thing going on here too. Celtic have gone from “everything going in” in 16/17 to “can’t hit barn door”.

But let’s look at Expected Goals to see if this is a slump in chance creation quality, or something else.

Celtic – Expected Metrics

Ah, at last some Green!

So, it turns out Celtic have been creating slightly better-quality chances and taking slightly better-quality shots! You don’t believe me, do you?

In Rodger’s first season his team outperformed their xG by a whopping 11 goals in the SPFL. Everything seemed to go for Celtic. You may remember the 5-0 title clinching win away to Heart of Midlothian. Celtic scored from all 5 shots on target. The total xG in that game for Celtic was only 1.78. You won’t get many days like that.

And thus, it came to pass that in 2017/18 Celtic underperformed their xG by 3.39 goals. This season, Celtic are already 4.88 goals under what we should expect.

This is “good news” in the sense that Celtic are actually improving their chance creation and shooting opportunities. It would be worse if chances were not being created to miss!

Whether it is inspired defending / goalkeeping, lack of confidence from the shooters or just luck that plays a large part in such a low scoring sport, Celtic look due for a regression to the mean. Which in this case should hopefully mean a few more chances going in.

Opposition – Creativity

Rodger’s has stated he believes the standard of the opposition has improved and that this may be a factor in Celtic’s declining performances.

The opposition are having slightly more possession but completing 14% less passes with it. The amount of chances being created by Celtic has actually decreased over time.

And like Celtic, the Total Impect has collapsed.

This suggests a style shift in opposition play. Last season Hibernian went toe to toe with Celtic employing a high press and trying to play through the lines. Although Celtic have not played them yet, the trend against Celtic seems to be to sit in deep and then play more direct passes. Hence the Total Impect and number of passes completed both diminishing.

Teams also want to avoid situations where Celtic can break on them as the Hoops are lethal in those situations.

Teams are successfully stopping Celtic more effectively but not being significantly more creative themselves.

Opposition – Goal Threat

Celtic are conceding no more goals than a year ago but the opposition hare creating slightly more chances and having more shots.

Overall shots totals are very similar and indeed Shot Accuracy hasn’t increased.

But the stand out is once again Shot Conversion. Mirroring Celtic’s performance in reverse, opposition shot conversion has sky rocketed from 18% to 33%. That despite a small drop in overall shot conversion.

Suddenly the shots are going in for the opposition. Is that sustainable?

We need to look at the Expected Goals metrics for that.

Opposition – Expected Metrics

The % values may look quite high but in real terms the opposition are creating no better chances or taking on no better-quality shots that previously. It is just that more are going it.

Think about Sunday’s defeat to Kilmarnock. Burkes shot could not have been placed better, hitting the post before going in. It was a 5% scoring chance at best and is not highly repeatable. Similarly, the headed goal from the corner is at best a 6% chance.

It may sound over simple, but Celtic can’t buy a goal despite creating the chances, and the opposition are seeing a massive up tick in shots going in despite not creating any better chances.

Conclusion

Celtic’s attacking productivity has fallen sharply across a range of key measures. They are not delivering on the chances created. The good news is chance creation quality is actually improving. Celtic are experiencing a huge underperformance relative to the goals they are expected to get. At the same time, the opposition have modestly improved, but are taking their chances at a massively improved rate. History suggests that those trends will adjust back to the respective means over time. That should mean more goals scored for Celtic and less conceded.

That is not to say Celtic’s current form decline is due to dumb luck. Celtic are playing too slowly, and have not adjusted well to deeper lying defences. Celtic lack an option to go direct due to Dembele’s departure. Opposition defensive shape has also limited Celtic’s lethal fast breaks. Play has become predictable as well as slower. Until those factors are addressed Celtic may continue to be on the wrong end of the expected goals models.

Change your own luck, Celtic.