This may seem like an odd question.

After all, Celtic are three points clear at the top of the Scottish Premiership with a game in hand. They are also well placed in the Scottish Cup; with a quarter-final against mid-table Championship side Greenock Morton to come. Indeed, they might have progressed to the final of the League Cup too but for an early red card in the semi, yet Ronny Deila is under severe pressure.

Celtic have seemed to underperform constantly. The perceived difference in quality between them and the rest of Scottish football means that many people expect them to win the league at a canter, triumph in both cups and most importantly make at least the group stage of the Champions League every season.

The main issue for Deila appears to be the improvement of Aberdeen. In fact in 2014/15 Aberdeen actually had a better record against the other 10 teams in the Scottish Premiership before the title was won:

It is common to hear that since Rangers’ demotion Celtic do not have any genuine competition. However, this is clearly not true at the moment, with Aberdeen capable of taking points off Deila’s side as well as the others in the division. Already this season they have taken six points from Celtic and if they can replicate their form from the rest of 2014/15 against the other clubs they would have a great chance of pushing the Glasgow giants all the way.

One of the main issues for Celtic this term has been their apparent inability to compete in Europe.

Their catastrophic exit from the Champions League at the hands of Malmo in the final qualifying round saw them drop down into the Europa League. Here they faced a tough group composition in Ajax, Fenerbahçe and Molde, but failed to pick up a single victory, losing three and drawing three to finish bottom. In fact in all European games going back to November 2014 they have won just four of seventeen, with two of those coming against Icelandic part-timers Stjarnan. This is simply not good enough and is a clear reason why Deila is feeling the pressure.

Add to this Celtic’s spending power, which is another reason that many feel they really should be the dominant force in Scottish football. As a case in point, the January signing of Erik Sviatchenko for £1.75m was almost double what the other eleven Premiership teams have spent combined in the last five years!

So why have Celtic struggled so badly this season?

One thing the fans grumble about is Ronny Deila’s insistence on a 4-2-3-1 formation.

When used correctly this can be one of the more dominant tactics and is the standard for many of the top teams in Europe. However, many of the best often transition into a more fluid 4-3-3 when attacking, which is something Celtic rarely do.

Deila often relies on Leigh Griffiths to lead the line, but he is often an isolated figure and it is only his incredible recent form which has allowed him to hit 30 goals already this season (22 in the league). In comparison, Celtic’s second top scorer Tom Rogić has just six league goals.

The issue with Celtic’s domination of the ball is that it often allows the opposition time to drop into a defensive shell, giving very little space around the box and making it hard for The Hoops to break them down.

Most of the other teams in the Premiership – with the exception of Aberdeen and Hearts – tend to approach playing Celtic like a lower league team playing a higher division team in the cup would. This means they want to stay in the game as long as possible by allowing no space for them to break into. Celtic then typically resort to more direct balls into the box in the hope that Griffiths can get on the end of them.

As a result, Deila’s side do not have the same level of dominance you would expect for a team in their position, especially when at home. They have only scored more than three goals on four occasions at Parkhead this season (see some of the other top teams in Europe for comparative purposes below):

This shows that though Celtic are winning the vast majority of their home games they are still struggling to break teams down effectively.

They often experience a lot of stagnant possession as they keep the ball for the sake of it in unthreatening areas, which vastly inflates their %. However, this is not a true reflection of dominance or quality, as the opposition will very rarely press until Celtic reach their defensive third.

Having two holding midfielders in the 4-2-3-1 formation (usually Nir Bitton and Scott Brown) is largely to blame for this and also means they lose an extra attacking option higher up the pitch. Indeed, the abundance of attacking midfielders within the Celtic squad also has the potential to cause issues too. While Deila always plays at least three of these types, they have ten who can operate in these positions. Even with the team likely to play a lot of games over the season this could lead to several unhappy players if they do not rotate and it can impact on cohesion if they do.

Despite the unpopular formation, it looks hard to criticise Celtic for their defensive work.

Following the home defeat to Hamilton in October 2014 they went on to concede just 12 goals in the next 28 home Premiership games at Celtic Park. This is perhaps to be expected, with very few teams actively attacking them in Glasgow and most being ecstatic to leave with a 0-0 draw.

The issue seems to come when teams do attack them, though.

As Celtic rely on their full-backs to push very high by making overlapping runs on a constant basis they look for one of the central midfielders to drop into the space between the centre-backs. This makes a third man and one that can pick up and distribute the ball from deep.

However this rarely happens and instead if Celtic lose the ball they can get caught with eight of their men ahead of play. This isolates the central defenders; usually Dedryck Boyata and Jozo Simunovic, and can lead to problems against a solitary striker with pace. Simunovic has taken some time to settle and Boyata is error-prone, he has contributed either directly or indirectly to a number of opposition goals this season. It is a far cry from 14/15, when Celtic had Jason Denayer and Virgil van Dijk playing on a regular basis and when Craig Gordon had every right to feel safe in goal.

Deila expects his defenders to be comfortable on the ball and van Dijk often burst out of defence to start attacks when at the club, with the opposition not knowing who was supposed to be picking him up. Simunovic has the potential to do this, but Boyata is poor with the ball at his feet and tends to put his team in trouble when playing out from the back, often relying on his pace to recover his position and/or the ball after losing it.

Despite struggling to break teams down as much as would be expected and conceding cheap goals, the graph below shows Celtic’s over-performance in terms of goal difference. Using metrics from StrataBet we can see that Celtic should have scored just 52 goals from the shots they have taken, but in fact they have actually scored 66. Likewise they should have conceded 25 goals, but have only let in 21:

This level of over-performance is likely to be unsustainable and looks inflated due to the number of Attempts they have scored. This is further boosted by Celtic’s ratio at actually converting these Attempts. A conversion rate of 5.2% is not too outstanding, but the sheer volume of Attempts they have puts this into perspective:

So while Celtic have converted a large amount of chances that we would not normally expect them to, the number of Attempts they have sees this rate at a level which is not statistically significant (typically we would expect a conversion average of around 2.5%).

The fact that Deila’s team have registered so many Attempts is again perhaps to do with how other teams set up against them.

They have a lot of shots from areas that are not conducive to scoring goals, mainly due to not being able to get into better positions because of the number of defensive bodies ahead of them. They have still made the highest number of Great and Good chances combined at 198 (Aberdeen follow on 160) but the table below shows the ratio of Great and Good chances compared to Attempts:

If Celtic continue to shoot from range, they are likely to see a dip in conversion at some point.

Another issue for Deila this season has been his goalkeeper. Gordon has been left exposed continually and after picking up several honours last year his performances have seen him criticised quite severely in the press, with the general feeling being that his indecisiveness has cost Celtic on several occasions.

In defence of Gordon, though, we earlier suggested that we would have expected Celtic to have conceded around 5 goals more than they have. Part of this must be attributed to the goalkeeper, so we can also look at his save % as a rough measure:

This table shows the Celtic stopper behind only Neil Alexander of Hearts and Danny Ward/Scott Brown of Aberdeen (Ward was considered the best goalkeeper in Scotland during his loan spell until the middle of January). Gordon has made a high number of saves compared to the number of shots on target he has faced, with a league average of ~71%.

So where does this leave Celtic and what options are there for traders during the rest of the season?

In the short term it appears that there is actually very little wrong with Celtic on a fundamental level. They have over-performed in the league both offensively and defensively, but weak individual performances in important games have cost them.

They still need to find a way to draw the opposition out in order to be able to play the way they want, instead of having to play through nine or ten players camped inside of the final third.

Are they still likely to win the league?

The “smart money” seems to say so, yes.

Their best title odds are still as low as 1.08 in most places (meaning the bookmakers give them around 92.5% probability of winning the title). Aberdeen now sit three points further back after defeat to Inverness Caledonian Thistle on Monday, but are around 9.00 (~11% probability).

Aberdeen seem incredibly good value given their recent improvement against their title rivals, though when they meet again it will be at Parkhead. Celtic’s over-performance could see them slip slightly, while Aberdeen’s ability to concentrate on the league after exiting both cups should also be taken into consideration.

If Aberdeen continue to play to their capabilities we could see the champions of Scotland coming from outside of Glasgow for the first time since 1985.

Dave Willoughby (@donceno)