From Flying to Falling

After an impressive 11-game unbeaten start to the league campaign, Aberdeen have now gone 14 matches without a win. What has gone wrong at Pittodrie? We dive into the data to find out.

As the 2024/25 season kicked off, few could have predicted the transformative impact Jimmy Thelin would have on Aberdeen FC. After a challenging previous campaign, Thelin’s arrival injected a fresh sense of purpose and tactical clarity into the Dons. Known for his meticulous preparation and high-intensity style, the Swedish manager has wasted no time making his mark at Pittodrie.

Through a combination of shrewd recruitment, tactical discipline, and a rejuvenated squad spirit, Aberdeen stormed out of the gates, showcasing a brand of football that blends defensive solidity with attacking intent.

However, their form has completely flipped, and they have been without a league win since November 9th. In this article, we analyse their season so far and delve into the data to uncover the reasons behind their dramatic downturn in form.

Let take a dive into the data!

The above chart analyses the performance of Aberdeen in the Premiership from the beginning of Thelin’s reign at the start of the season, to end of January, based on expected goals (xG) and expected goals conceded (xG Conceded).

xG (green line): Indicates a decline in the team's attacking quality over the period. The trendline shows a steady decrease, implying reduced scoring opportunities or quality of chances created.

xG Conceded (pink line): Shows a significant increase over time, highlighting a deteriorating defensive performance as the season progresses.

The trendline reveals a significant negative shift in both attacking and defensive outputs, which has undoubtedly influenced Aberdeen's results this season. This alarming trend signals major concerns for the coaching staff, who must act swiftly to address these issues and prevent further decline. The data paints a picture of a team struggling to maintain its competitive edge, with both ends of the pitch contributing to their current troubles.

Now, let’s take a closer look at their attacking and defensive performances individually to understand where the cracks are forming.

Defending

This data visualisation compares Aberdeen's defensive metrics over two periods of the 2024/25 Premiership season: early season (August 5 - November 1) GREEN and mid season (November 9 - January 25) RED.

Aberdeen's defensive metrics have declined sharply in the mid part of the season, with higher xG Conceded, more shots allowed, and significant vulnerability to clear chances. Despite minor improvements in pressing and set-piece defense, the team struggles to maintain a compact structure and manage counter-attacks effectively. These trends highlight the urgent need for tactical & personnel adjustments to tighten the defense and reduce the quality of chances afforded to opponents.

The above shot maps compares shots against Aberdeen during two periods of the 2024/25 Premiership season: August 5 - November 1 (left) and November 9 - January 25 (right). It provides insights into the quality, type, and location of chances conceded

Aberdeen's defensive performance has declined dramatically compared to the early part of the season. Opponents have capitalised on clear vulnerabilities in set-piece defense, through balls, and open-play crosses, leading to a significant increase in xG -more than doubling - and a sharp rise in goals conceded. My take from this analysis is the defensive structure has struggled to contain central, high-quality opportunities near the goal, leaving the team increasingly exposed and vulnerable.

Comparing Aberdeen to the current bottom side St Johnstone, both teams face defensive challenges but their approaches differ significantly. Aberdeen’s aggressive and proactive defensive strategy, characterised by a higher line and moderate pressing, has struggled to translate into effectiveness, leaving them exposed to counter-attacks, high-quality chances, and set-piece vulnerabilities.

In contrast, St Johnstone’s deeper, more compact approach provides better control of shot quality and set-piece defense, albeit at the cost of allowing slightly more clear-cut chances.

Should Thelin take a more conservative defensive approach? Let us know in the comments!

Attacking

Again we use the above data visualisation to compare how Aberdeen are attacking in both early and mid season periods. Both periods are indicated: early season (August 5 - November 1) GREEN and mid season (November 9 - January 25) RED.

Aberdeen's attacking output has noticeably declined in the latter half of the season. Their xG per 90 has dropped significantly, and shot quality (xG/shot) has worsened, reflecting inefficiency in finishing and chance creation. Key issues include a lack of clear shooting opportunities and below-average counter-attacking effectiveness. While box cross success has slightly improved, it hasn’t offset the broader struggles in attack.

As with our defending analysis, we look at shot maps to assess their attacking proficency over the two periods this season.

Aberdeen’s attack has increased its shot volume in the mid season period but at the cost of quality, as shown by a reduced xG per shot and diminished finishing efficiency. While set pieces and open-play crosses have become more productive in terms of xG, they still lack the necessary conversion to make a decisive impact. The team’s reliance on low-xG, speculative efforts, and a noticeable decline in through ball effectiveness underscore significant inefficiencies in both chance creation and execution. Essentially, Aberdeen is prioritising quantity over quality, resorting to "shoot on sight" tactics rather than crafting higher-quality opportunities closer to goal.

Why?

One reason that appears to be apparent in the downward trajectory of form, is key players missing from the starting 11.

Their first-choice goalkeeper, Dimitar Mitov, suffered a hamstring injury in early December, paving the way for backup goalkeeper Ross Doohan to step in. As the scatter plot illustrates, Mitov has been relatively reliable under significant pressure, performing admirably despite facing a high volume of shots. In contrast, Doohan has struggled to rise to the occasion, conceding more goals than expected given the number of shots he has faced, highlighting a noticeable drop in goalkeeping performance during Mitov's absence.

At the other end of the pitch, Pape Habib Gueye sustained an injury in early October, sidelining him for 14 matches. Despite missing a significant portion of the season, he remains Aberdeen’s top scorer in the league, underscoring his importance to the team’s attack. This highlights a concerning lack of form from other attacking players and reveals the team’s heavy reliance on Gueye to deliver goals, exposing a critical weakness in their offensive depth and output.

Additionally, one could argue that the physiological impact of each loss is taking a significant toll on the squad, much like how Manchester City have struggled this season. With every game that passes without a win, the team's confidence continues to erode, and this is increasingly evident in their performances on the pitch.

Conclusion

In an effort to address the dramatic dip in form, the Aberdeen coaching staff made key additions to both ends of the starting XI during the January transfer window. However, as the table below highlights, these new signings are untested in the Scottish Premiership and are either approaching or just below their peak age. This brings an element of risk, as their ability to adapt quickly to the league and make an immediate impact remains uncertain.

With the second half of the season underway, the big question remains: can Aberdeen turn their season around and prove that Jimmy Thelin’s promising start wasn’t a false dawn? Or will their struggles continue, leaving them vulnerable to a disappointing finish?

Let us know your thoughts—what changes do you think Aberdeen needs to make to get back on track? Leave your ideas in the comments below!