Understanding the Ange Postecoglou Celtic fundamentals at core of double-winning debut season

Does it even exist, or is it just excitable fan affectation? If it does exist, then what are its characteristics?

We now have one campaign's worth of data in the can for an Ange Postecgolou Celtic side. Do the overall team-level numbers differ in a way that helps us to answer these questions?

Successive treble-winning seasons leave you little room for growth in terms of comparisons with what has gone before.

Postecoglou defied many fans’ expectations with a title win given the sheer size of the rebuild and the relative stability of their primary domestic opponents. A cup win and European football past new year were also unexpected bonuses.

In terms of overall results, there have been more stellar recent seasons though:

Points percentage is calculated by assuming every match is a quest for three points and reflects the percentage of points 'won' on that basis.

Is this underwhelming? Well, what we have learned is that focusing on results over performances does not tell you whether a team's fundamentals are solid or not.

What are the primary performance differences though?

Control and pass aggression

Aspects of the style of play can be identified from some basic metrics.

In this case, let’s look at overall possession as a proxy for 'control' and packing score as a proxy for 'forward passing aggression'.

While Rogers was all about controlling possession, his teams were relatively conservative when it came to getting the ball forward through the lines. Patience, field position and probing were the watchwords. Possession got near 70 per cent by season three.

Lennon wanted the team to get the ball forward quicker and was not greatly enamoured by 'tippy-tappy passing the ball about for the sake of it', as he’d maybe characterise it.

What Postecoglou seems to have achieved is a balance between possession (65 per cent) yet with an emphasis on forward pass penetration. The pass packing score average his side has achieved is by some way the highest since I started recording this data (470 pack score is 118 higher per 90 minutes than Lennon’s 2019-20 side).

Although Postecoglou’s men enjoyed a high degree of control and completed many passes, they also played the highest proportion of completed passes that take opponents out of the game:

Fifteen per cent of all completed passes take at least one opponent out of the game. And, crucially, they are forward passes in the right areas of the field. We can measure this by recording how many opposition defenders are taken out by forward passes, indicating aggressive last-third passing.

It will be fascinating to see how much Postecoglou can further optimise this balance between control and possession with aggressive forward passing.

Attack

Has Postecoglou improved Celtic's attacking play? Looking at basic shooting stats would lead you to think 'perhaps not':

Shot accuracy (percentage of shots on target), shot conversion (percentage of on-target shots resulting in goals and percentage of all shots resulting in goals) have varied little over different regimes. Postecoglou has, at least, brought levels back towards 2019-20 numbers.

Postecoglou’s side seems a little shot-shy in comparison to Ronny Deila and Rodgers' teams. Although, again, seasonal numbers fluctuate within quite a narrow range from 16-19 shots per 90 minutes.

READ MORE: Assessing Celtic’s fringe players and where Ange Postecoglou must be ruthless

More important is the quality of shots taken. Inevitably then we consider expected goals (xG) for this:

That’s more like it. By some distance (well, 0.01 per shot) this current Celtic side is taking better quality shots. This does not happen by accident.

This version of Celtic is getting more possession of the ball in the opposition box and, consequently, attempting more shots from there.

They may not be generating any more shots or even being more accurate or clinical with them, but the fundamentals of where shots are being taken from and therefore the quality of those shots is increasing. Which is smart.

Chances

As you would expect given the above, Celtic are not creating more or fewer chances per 90 minutes than has been the trend over recent seasons.

However, the quality of those chances is best in recent class:

Big chances are those where a reasonable person might expect the player to score. Think of a “and Smith must score” type of scenario from a commentator. Needless to say, creating big chances is a good thing.

Expected assists (xA) is a measure of the quality of a shot resulting from a pass. Both these metrics show up well for this season and indeed lead the field over Rodgers and Lennon’s sides. How is this being achieved?

Celtic are putting in more crosses – well over 20 attempted per 90 minutes – although only 3.12 are successful on average.

They are also increasing the number of passes played into the danger zone (the area central to the goal and up to the edge of the 18-yard box).

Postecoglou is, then, getting his side to play more passes into areas where the team is more likely to score.

When you read that back you think 'well that’s obvious why don’t all teams do this more?' Two observations: 1) Football is dumb; 2) It's easier said than done as clearly opposing teams don’t want you to play like that.

Press resistance

Finally, when we talk about 'bravery on the ball' it means a few different things: keep possession and don’t needlessly give the ball away while simultaneously looking to play aggressive forward passes... while simultaneously being comfortable playing out under opposition pressure.

We’ve seen the evidence for the former characteristics. For the latter, passes per defensive action is a useful proxy. This is the number of completed passes per opposition defensive action.

This particular stat is one worth keeping in mind when thinking about performances in Europe. Better teams will tend to press more aggressively and be better organised about it.

Becoming more competent playing out under that pressure augurs well for playing against higher-quality opponents in Europe.

Summary

Based on season one of 'Ange-ball', we could characterise the phenomenon as:

• Optimising the balance between controlling possession and breaking opponents’ defensive lines with aggressive forward passes
• Better quality shot selection and getting players into optimal scoring positions
• Playing passes into areas that will generate the highest xG chances
• Being 'brave' on the ball to maintain possession and forward momentum despite opposition pressure.

One word to distil 'Ange-ball'? Smart. This Celtic side is playing clever football within a consistent and coherent playing style.

With more practice, better player understanding and more suitable players for the style, the underlying performance data improvements should manifest in better results over time.