Analysis Corner: Are Celtic in a slump? Or have they just hit a red light?

Have Celtic hit a slump? It’s a strange position when the league leaders are described as being in a “slump”. Even more so when they are eleven points ahead of the nearest competitor, with two games in hand.

Published 20th Dec 2016
Last updated 28th Mar 2017

By Dougie Wright (@dougie_analysis)

Have Celtic hit a slump?

It’s a strange position when the league leaders are described as being in a “slump”. Even more so when they are eleven points ahead of the nearest competitor, with two games in hand.

However, of Celtic’s last five Scottish Premiership games, all against sides in the bottom half of the table, four have been won by a solitary goal. Comparing their goals per game from the first five games of the season to the last five, Celtic’s production has dropped by a goal.

To be clear: any other team in world football would love to hit a “slump” where you’re still scoring goals and winning games. It is nevertheless clear that Celtic are struggling to rack up scorelines as impressive as they did at the start of the season. So what’s caused this?

The simple answer is variance. Variance is a statistical theory that underpins most aspects of daily life. From your drive to work to your gambling winnings, variance is the unseen hand working away in the background any time randomness is involved. It’s also dead simple to understand.

To use the drive to work example, let’s say you live 10 miles from work and it usually takes you 20 minutes to get there. Some days you’ll hit every red light going. Others, you might get pulled over by the police. Occasionally, you may have to take a diversion. When these things happen, the drive takes a good half hour. However, if there’s no traffic on the road and all the lights are green, you might be able to do it in 15 minutes.

These are all things beyond your control that affect the outcome, and the same can be said about shooting in football matches. On some days, you’ll face a keeper in great form. For example, at the weekend Scott Bain made five good saves for Dundee to keep Celtic on their toes. Others, your team may have left their shooting boots at home: against Hamilton Accies, thirteen of Celtic’s fifteen shots missed the target.

To provide an opposite example, earlier in the season Celtic scored four goals from ten shots against Aberdeen. Indeed, in that game, just one of their five shots on target failed to find the net.

Despite all this, it’s clear that Celtic are still the team to beat. Since people started tracking shots eleven years ago, no team has taken more per game than Celtic this season:

Generally, shots get turned into goals at a rate of between 10% and 15% over the course of a season. That means that for every ten shots a team takes, they should score at least once, possibly twice. Currently Celtic average 18.5 shots per game, which means that they should usually end up scoring twice on a bad day, three on an average one, and four on a good one.

Celtic had a lot of good days at the start of the season, as well as a couple of excellent ones. To hit a few red lights after a run like that is totally normal. Sadly, for the rest of the league, those red lights are not enough to stop Brendan Rodgers’ team from taking home the three points.

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