Celtic’s league record since Ange Postecoglou’s arrival has gone from strength to strength, including what is now over a year and a half without a home defeat.

Underlying performance metrics such as expected goals have aligned with the dominance. Giorgos Giakoumakis’ recent comments at his initial Atlanta United press conference about the typical tactics of Celtic’s opposition drew some attention and indeed the relative defensiveness of opponents has remained consistent.

Over the 10 league games since the return from last year’s World Cup, only Hibernian and Rangers have not set up their defensive alignment with a back five.

READ MORE: How Cameron Carter-Vickers' Celtic performances compare to last season

While high-level chance creation at a high average quality has been a hallmark of the Postecoglou era overall, this period has begun to show some notable deterioration. 

While the period included nine wins and just a single draw, at Ibrox, as well as a cumulative goal tally of 28 to just five it did include the two victories over Aberdeen and Livingston by a single goal. Defensive resiliency has remained relatively stout but chance creation has been on a bit of a slide:

Celtic Way:

The first graphic shows the non-penalty xG and xG from open play for each league game this season to date, with regressed trendlines included for both. Seven of the 10 games have had those metrics below trend post-World Cup.

If we go back to the beginning of Postecoglou’s tenure and look at a six-game moving average of these metrics, we see the following:

Celtic Way:

The decline to a new low could be of theoretical concern and it certainly does not appear to align with the collective mood among the Celtic support given the current lead in the league table. 

Here is a radar comparing the first 15 league games prior to Qatar and the subsequent 10:

Celtic Way:

To place this relative deterioration in chance creation into some additional perspective, including how elevated performance levels have been under Postecoglou prior to this stretch, the following table provides analogous season segments starting in 2018-19:

Celtic Way:

We can see from this table that Celtic’s post-World Cup performance levels have come back to earth from what had been very elevated output.

A high level of goalscoring has masked this decline and obviously contributed to the excellent stretch of results.

Even compared to this period last season, in which the squad suffered from significant injuries and a relative lack of depth, chance creation has been down.   

Yet while Celtic’s chance creation has declined, it appears to have come at an opportunity cost among their opponents as their collective move to combat ‘Ange-ball’ with intense defensive tactics has correlated with npxG conceded down to 0.43 and a minuscule 0.30 from open play. In fact, Joe Hart has faced fewer than 1.5 shots on target per game over the period.

Celtic Way:

Such is the difficulty most domestic opponents confront when staring down Postecoglou’s Celtic.

In order to make a dent in slowing the chance-creating juggernaut, the ability to threaten the champions’ goal has almost become as rare as a home defeat at Parkhead.

The upcoming derby matches should offer valuable litmus tests as to whether the recent slide in chance creation may have more expansive causes.

Remember, however, that the probability of Celtic losing non-derby matches should remain extremely low even if the current performance trends highlighted here persist.