Why it all ended up so wrong for Neil Lennon at Celtic

Neil Lennon, Celtic. (Photo by Ian MacNicol/Getty Images)
Neil Lennon, Celtic. (Photo by Ian MacNicol/Getty Images) /

It’s fair to say that the 20/21 season for Celtic under boss Neil Lennon has been an absolute disaster that nobody could have seen coming. However, with change now in motion there is hope that things could take an upturn soon.

We wanted to examine the data behind this season to try and pinpoint just exactly what has gone so wrong compared to last season. Hopefully this should give the fans some explanation as to what has happened to the Hoops and how they need to improve under the next manager.

For the time being that guy looks like John Kennedy, who will take interim charge. But hopefully the club will bring in a more experienced manager at the end of the campaign, who can guide them back to the top of Scottish football.

All data is sourced from Wyscout

Celtic’s attack has taken a step back

This season it has felt as if our forwards just haven’t been firing on all cylinders. This is reflected by our output in front of goal. This season Celtic have only amassed 1.96 goals P90, with xG being 1.94 P90.

This means the club, on average, are scoring around the expected amount of goals for the chances we create. Looking back to last season it’s clear output has declined significantly with the 19/20 campaign yielding 2.58 goals P90, corresponding to 2.2xG P90.

Even though Celtic were overperforming there expected goal output last season it is still a decline of 0.26xG P90. And as you’ll notice, the creativity has dried up a bit as well.

Their deteriorating defence

Now xG is important but limiting the opposition to as few chances as possible is just as vital. However between this season and last a decline was also experienced in this area.

This season Celtic conceded 1.22 goals P90 with an xGA (expected goals against) of 1.12. This means we are conceding more goals than the xG generated by the opposition. The underperformance in this metric isn’t  a good look for goalkeepers or the defence.

Last season, the Hoops only conceded 0.77 goal P90 with an xGA of 0.88. Like goals scored, Celtic had overperformed in keeping the ball out of the net. Overall XGA rose from 0.88 to 1.12 – a difference of 0.24.

The xG Differential

To be successful the xG differential has to be as high as possible. This helps to negate some of the random nature of football such as wonder goals, penalties and red cards to name a few. xG differential is the difference between xG & xGA. Or in simpler terms, create more goalscoring situations than the opposition team, the aim of any football game.

This season the differential has been 0.82 whereas last season it was 1.32. With this it is clear, that it is no surprise Celtic began to lose points at a higher rate. A reduction of 0.5 in this category indicates systemic problems across the pitch that ultimately led to poorer performances.

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Overall Celtic’s xG fell by 0.26 & xGA rose by 0.24. With the xG differential gap reduced by 0.5 the variance in results became more extreme. By this, we mean they became more random, where we weren’t as probable to guarantee a result.

Although just a glimpse at the data it is clear Celtic have underperformed and declined from last season, we have less good goal scoring opportunities and also give more good opportunities away. From front to back there has been a decline and likely there are many reasons for this, from; formation changes to playing players out of position and many more.

Next season we need to be more creative and clinical in front of goal and reduce the opposition to fewer good quality chances. It will be a tough task for the new manager with the rebuild required. Hopefully it will be an improvement from the data seen this season.

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