In this data analysis, we will delve into the statistics of centre-backs currently playing in the Scottish Premiership and identify those with the potential to earn a move to one of Europe’s top leagues. All players included in this analysis have played a minimum of 900 minutes in the 2019/20 season.
Liverpool‘s Virgil Van Dijk is widely regarded as one of the best defenders in the world and he once plied his trade in Scotland at Celtic for two seasons before securing his big move south of the border to Southampton. Alongside Van Dijk, several other centre-backs have made the journey from Scotland’s top tier to the English Premier League: Jean-Alain Boumsong, David Weir, Carlos Cuéllar, and Alan Hansen, just to name a few. Whether it’s Hansen in the 1970s or Van Dijk in the 2010s, the SPL keeps on churning out centre-backs capable of playing at the very highest level. This data analysis will provide a sneak-peek into who could be the next elite level centre-back to depart Scotland.
Possibly the most crucial attribute of a modern-day, commanding centre-back, is their ability to successfully win their duels. We will start our analysis by studying defensive duels per 90 and the percentage of defensive duels won. For clarity, a defensive duel is when a defender challenges an attacking player for the ball whilst the ball is on the ground.
Several players are to be noted from this scatter graph.
The 35-year-old Kilmarnock defender Kirk Broadfoot is a clear stand-out, winning an impressive 83.58% of his defensive duels, although he is one of the lowest in terms of defensive duels per 90, 4.66. Celtic duo Kristoffer Ajer (78.40%) and Christopher Jullien (76.88%) also both win in excess of 75% of their defensive duels, Ajer with slightly more duels per 90 at 6.22 compared to Jullien’s 5.57.
The average for this statistic comparison is 6.54 duels per 90 and 71% of duels won.
Declan Gallagher (74.26% of 8.48 duels per 90) and Jon Guthrie (74.03% of 7.85 duels per 90), along with St. Johnstone pairing Jason Kerr (74.81% from 7.56 duels per 90) and Liam Gordon (74.85% of his 8.22 duels per 90), are also worthy of a mention due to the fact they contest a high number of duels and are successful in a fairly high percentage of them.
At the opposite end of the graph, we see that Connor Goldson of Rangers contests the least number of duels per 90, 4.21, and only wins a below-average 63.27%. Wallace Duffy and Darren Mcgregor both contest a high number of duels yet are only successful in under 60%.
A key component of a great centre-back is being dominant in the air. In the next scatter graph, we are looking at aerial duels per 90 and the percentage of aerial duels won. An aerial duel is where players from opposing teams compete for a ball in the air.
Celtic are the dominant team here, with three of the top four all playing for the Bhoys. Nir Bitton leads the way for percentage of duels won with 78.26% but also contests the least aerial duels per 90 with only 3.99.
Ash Taylor of Aberdeen, scores very well in the graph above. The former Tranmere Rovers man is the only other player, besides Bitton, to win in excess of 75% of his aerial duels. Taylor wins 75.63% of his 8.71 aerial duels per 90.
Frenchman Christopher Jullien ranks highly again, contesting 8.36 duels per 90 and coming out on top in 73.75% of them.
The averages for this statistic are 7.73 aerial duels per 90 and 64.97% of duels won.
Kirk Broadfoot, who won the most defensive duels, won the lowest percentage of his aerial duels. Goldson, Kerr, and Gordon all score around average in both areas. Jon Guthrie contests the second-most aerial duels with 11.29 per 90.
To measure football intelligence, we are going to analyse the data for shots blocked and interceptions. The ability to read the game and anticipate the opposition’s next move is an integral aspect of what makes a centre-back world-class.
Two players that immediately stand out here are Jamie Mccart who makes 10.84 interceptions per 90 as well as 0.66 blocks per 90 and Adam Jackson who blocks 1.76 shots per 90 and makes 6.54 interceptions per 90.
Keith Watson has good scores in both areas (7.47 interceptions and 0.92 blocks per 90) as well as Sean Mcloughlin (6.95 interceptions and 0.86 blocks per 90) on loan at St. Mirren from Hull City. Callum Morris also has decent stats in this area (6.79 interceptions and 0.86 blocks per 90).
If we look back at some of the highlighted players from earlier, it is surprising to see Norwegian prodigy Ajer ranked as the lowest in both interceptions per 90 (3.27) and blocked shots per 90 (0.26). This may be due to Celtic’s tactics having an influence on Ajer scoring so low. Celtic are a possession-based team, meaning that defenders from these high possession team will naturally have fewer interceptions and blocked shots as, quite simply, their team is in possession more often than others.
The average for this graph is 6.12 interceptions per 90 and 0.66 shots blocked per 90. A few players we have mentioned earlier are all close to this average.
Looking back upon our analysis into the defending data. We have a few players that have been highlighted in several areas.
The Celtic trio of Ajer, Bitton, and Jullien have all appeared more than once. Ash Taylor also has good underlying data of his defensive performances. Surprisingly, none of Steven Gerrard’s Rangers players posted anything higher than an average score.
Possession, possession, possession
In modern football central defenders don’t just have to defend well. It’s becoming more desirable for defenders to be ball-playing defenders, more often than not, completing the most passes in a match. If that wasn’t enough, players also need to have a very high pass completion percentage. In this next scatter graph, we will analyse completed passes per 90 and passing accuracy as a percentage.
No surprises here then: all six of the leading players are from one of the Glaswegian clubs, and the top four are all Celtic players. The two highest possession teams in the league are clearly some distance ahead of the 10 other teams in the Scottish Premiership. We’ll cover the top six briefly and then delve into the rest to find a strong passer at one of the other SPL teams.
Nir Bitton averages 69.17 passes per 90 with an accuracy of 90.72%. Jozo Šimunović completes 64.80 passes per 90 and edges out his Celtic teammate for accuracy with 90.74%. Ajer (60.8 at 90.2%) and Jullien (58.27 at 88.46%) round off the four Celtic defenders. Next up, Connor Goldson (57.43 at 86.47%) is the last of the five clear of the rest. 23-year-old Nikola Katić completes 46.92 passes per 90 with a strong accuracy of 85.40%.
Ryan Porteous is the first non-Old Firm player on the graph. The youngster has an impressive 85.82% passing accuracy and completes a steady 46.62 passes per 90. Other players to highlight from the pack are Porteous’ teammate, Paul Hanlon (40.85 at 83.23%) and Jamie Mccart (30.96 at 68.86%) who not only completes the least number of passes per 90 but also has the lowest passing accuracy.
The average passes per 90 is 37.37 and the average accuracy is 80.15%, showing that Mccart is well under the average from an accuracy point of view.
Following on from our previous graph showing passes per 90 and passing accuracy, we wanted to analyse which players make the most forward passes per 90. The scatter graph below shows passes per 90 and forward passes per 90.
Once again, the Glasgow teams dominate but when cross-referencing with the previous graph, we see slight changes at the top end. Bitton still remains clear of the others completing 27.34 forward passes per 90 whilst Ajer (21.76) and Jullien (19.82) are slightly lower. This is mainly due to Goldson, who completes the second most forward passes with 24.80. Motherwell centre-back Peter Hartley jumps out from the rest with over half of his 45.69 passes per 90 being forwards, 23.47. Ryan Porteous is also one of note successfully completing 19.83 forward passes per 90.
The average number of forward passes per 90 is 17.69.
The last possession-based stat that we are going to analyse is progressive actions per 90. The graph below shows progressive passes per 90 and progressive runs per 90. The further towards the top right-hand corner suggests the most progressive that the player is. If we factor in that centre-backs often make more touches than any other player on the pitch, what we want to see is who are the most efficient players at getting their team higher up the pitch.
Yet another graph dominated by the Celtic players. Due to the number of players with very similar numbers, only players that score high on this graph or those that we have previously mentioned are labelled.
Nir Bitton is the most progressive centre-back when combining his progressive passes and runs. The Israeli makes 11.54 progressive passes per 90 and 4.25 progressive runs per 90. Ajer and Šimunović both score high in opposite areas: Ajer (4.44 runs and 9.08 passes) and Šimunović (12.7 passes and 2.8 runs). Previously mentioned players Jullien, Porteous, Goldson, and Gallagher are all conveniently similar in terms of progressive actions with all players making between 1 – 1.6 progressive runs per 90 and between 9 – 10.50 progressive passes per 90.
Ash Taylor, who previously impressed in other stats, does not in terms of progressive actions. The average number of progressive runs per 90 is 0.87, which bodes well for Bitton, Ajer, and Šimunović. The average number of progressive passes is 8.70.
It’s a little bit of a cliché, but how often have we heard ‘big lads from the back’ just before an attacking set-piece. In the 2018/19 season, Craig Halkett scored the most goals by a centre-back, with seven goals. The graph below shows how many non-penalty goals have been scored by centre-backs this season along with shots per 90.
Whilst scoring goals isn’t a centre-back’s main responsibility, if he can chip in with a few goals over the course of a season, it is a bonus.
Jon Guthrie of Livingston has scored the most non-penalty goals with six, Christopher Jullien comes next with four goals. It is worth mentioning that Guthrie, Halkett, and Šimunović all average around one shot per 90.
Three player shortlist
So that’s all the data analysis done. Now we have got to pick out the best of the bunch. We’ve identified three players that could go on to secure that lucrative transfer to a top European league at some point in the future. Throughout this analysis, there were two players that were in the top bracket on several occasions and one other who was consistently in the bracket just below the leaders.
Kristoffer Ajer – The youngster is our first shortlisted player. It should not be understated that the Norwegian is only 22 years old and is likely to improve in the future. Virgil Van Dijk, in comparison, was 24 when he got his move to Southampton. From a data perspective, Ajer excels in his defensive duels, passing and progressive actions. He does seem to have a weakness when it comes to his reading of the game, as he scored low on blocked shots and interceptions. Ajer has a market value of £3 million (Wyscout) and for this price, there is every possibility that Ajer could follow in Van Dijk’s footsteps and move to a mid-table EPL team within a few years.
Christopher Jullien – There is no denying it – Celtic have the strongest centre-backs in the SPL. Like Ajer, Jullien is young enough to develop into an even better defender than he already is. The data suggests that Jullien’s strengths are in both defensive and aerial duels, passing, and the Frenchman is also a goal threat. There are no obvious weaknesses in his game. Celtic could easily demand a bigger fee than his market value of £6 million, according to Wyscout.
Ryan Porteous – The 21-year-old completes our shortlist, though there may be older players with better stats. Porteous has time on his side to develop his game. He is already posting solid numbers in several areas and had received his first call up to Scotland squad for the Euro 2020 qualifiers against Cyprus and Kazakhstan. From our analysis, we can see that he does need to improve in his defensive and aerial duels, but Porteous was frequently the first player away from Celtic and Rangers lads to show up in the possession data, with high scores in both interceptions per 90 and all aspects of his passing. Maybe the next move for Porteous is to get his move to Celtic or Rangers where he can continue to develop in a bigger team.
Special mention. Nir Bitton – The Israeli just missed out as Ajer’s, Jullien’s, and Porteous’ youth and potential to improve gave them the nod. Bitton is operating at a high level and at 28 years old, is at the peak of his career. If a top European club wanted an immediate fix for their defensive issues, Bitton may be a great option.
In this data analysis, we managed to identify three young centre-backs that are performing to a high level in the Scottish Premiership and whilst all three are young and need nurturing to be the world-class players they could develop into, they are worthy candidates. We also found a player in the peak of his powers, who would be a great addition to many teams in Europe’s top leagues.
Although data is a great tool for finding those players with strong baseline numbers, there are always two sides to the story, and we will produce a detailed scout report for the brightest prospect, Kristoffer Ajer.
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