Bhoys Analytics: How Ange Postecoglou can change Celtic

By John McGinley

June 3, 2021

On 67 Hail Hail we’ve brought you a variety of arguments for and against the Ange Postecoglou appointment at Celtic over the last few days, presenting our own opinions as well as speaking to journalists in Japan and Australia.

But what does the data say about his time at Yokohama F. Marinos?

The following analysis was researched and written by the ever superb Bhoys Analytics, who you can follow on Twitter for even more analysis and opinions @BhoysAnalytics.

This will show the data behind how Ange Postecoglou changed the Marinos from a mid-table side into champions and its relevance to Celtic.

Postecoglou, financial limitations and Marinos improvement

Ange is working with a budget that ranks 12th out of 18 teams and has them constantly overperforming, winning & competing for titles. Making up the financial gap in football with good managers is a vital step for any club wanting to compete above their means.

His first season was tough as he deployed his high-intensity possession-based style on a side that had never played this way before. After this transition year, Ange took his team to the title as other teams struggled to deal with the energy of his team.

Although underlying performances were good in 2020, his team fell victim to bad variance and conceded far more than they should have and dropped down the table. However, 2021 has seen Ange guide his team back to competing at the top of the table, currently sitting in 3rd with games in hand.

Postecoglou prefers offensive football. The number of goals and xG rise with his introduction and continue to steadily increase through his reign. His team’s defensive underperformance in 2020 can be seen clearly when comparing the 59 goals conceded with only 47.46xGA.

The 55-year-old is having his best spell as the Marinos’ manager this season. His philosophy is now the backbone of the club and that has led to a further rise in the number of expected goals. Since arriving, Ange has changed a team on an xG differential of -0.25 to 0.74.

Underlying changes in comparison to the Celtic Invincibles

These sections will look at more granular data metrics to show how Postecoglou succeeded in implementing his tactics and making a mid-table side champions. I have also included 16/17 Celtic invincible data in red for comparisons to Brendan Rodgers.

Offensive changes

Shots for have increased slightly while shots against are fairly constant. Combining this with rising xG data indicates that his side are creating better quality chances season on season.

Higher quality chance creation is shown by other metrics such as the percentage of shots from outside the box. Since Postecoglou came in, this has been steadily decreasing but shots have been going up. This indicates a desire to work the ball into better areas for higher quality chances.

The change in focus to quality chance creation is visible on the shot maps of Daizen Maeda (left) (LF) & Ado Onaiwu (right) (CF). There are very few long shots and the majority come from central areas where the probability of scoring is highest.

Getting the ball into and having possession in the opponent’s box are clear tactics. These all link to how his team attack with numerical equilibrium or superiority over the opposition defence. Average shot distance also decreased, so again higher quality chances.

On the ball changes

Postecoglou’s teams dominate games focusing on short passing and interplay to break through teams or working the ball into wide areas where they are deadly. He succeeded in taking the Marinos from 50% to over 60% average possession in just one season.

The increased domination is also shown in the large jump in average passes per game. More passes but less possession than Rodgers’ Invincibles suggests Postecoglou prefers to work the ball forward to create chances rather than patiently holding possession and wait for openings.

Stylistically we can see that the Marinos boss drastically changed how his team moves the ball around, preferring to hold onto it for longer and keep passing short and on the deck. These changes allowed his side to control games and I would expect similar to be done at Celtic.

This is reinforced when we see how even average pass length is reduced. Every player including the goalkeeper & centre-backs must be capable of this passing style. After one season, when the squad was his and had adjusted to his style, is when Yokohama really took off.

Game intensity

In every metric shown here, Postecoglou took the Marinos from mid-bottom of the table to the top. They all show his eagerness to play faster and put more pressure on his opponents. This is where the Marcelo Bielsa comparisons become apparent.

Match Tempo (Passes per minute of good possession) – His team move the ball around quickly and effectively. Even if a breakthrough doesn’t occur this can tire opponents out. From watching his team score quite a few late goals, I think this is a contributing factor.

PPDA (Passes per defensive action) – The higher the number the more they allow the opposition to pass the ball in their own half. The opposition will not have comfortable possession as his players will always be pressing hard and trying to win the ball back high up the pitch.

Challenge Intensity (Duels, tackles and interceptions per minute of opponent possession) – Just more indication of how much pressure Postecoglou’s team put on opposition outfits. It can be a dangerous game if the press is broken or the ball is lost in their own third.

Defensive

As expected, Postecoglou’s team are involved in more defensive duels as they make more of an effort to win the ball back. Aerial duels are generally down as well, suggesting again that the ball is played largely on the deck.

Conclusion: Strong tactical fit but it could take time

I think Postecoglou is a good tactical fit and it’s a shame the board may have ruined the introduction to an exciting attacking manager. I think fans will really take to his fun attacking style if given time.

However, I would expect, like the Marinos, a difficult first season as the squad is built and adapts to his philosophies and style. I hope the fans give him time because he has good ideas and plays football you want to watch.

Bhoys Analytics will have more data and video analysis on his Twitter account next week.