Looking for a Well Rounded Center Back in the Numbers

Kerr img.png

Written by: Matt Rhein/ @thebackpassrule

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At the beginning of this Premiership season, I looked at the passing behavior of center backs in the SPFL Premiership and which were best in their team’s attack. Given the trends across the world of football of the ball playing center back being more popular, it seemed worth examining who was the best ball playing center back in Scotland.

Of course, every team does not need a ball playing center back. Different teams have different styles with different requirements from their squad. Your favorite team might need a center back who will not let a single cross meet an opponent’s head and dominate the air. Or perhaps they need a tough tackling, no nonsense defender who does not need to pass his way out of a paper bag.

SPFL Premiership Center Back passing behavior 2018/2019 showing pass completion % & % of passes attempted leading to a shot.  Interactive version here .

SPFL Premiership Center Back passing behavior 2018/2019 showing pass completion % & % of passes attempted leading to a shot. Interactive version here.

Though what if we could find a player in Scotland who is capable of handling both his defensive duties and not be a hindrance to his club on attack? Thanks to the data provided by our pals at Ortec, we can delve into the statistics to see the best passing and defending center backs in the Premiership and if there are any defenders that are above average in both defending and passing.

In our article on passing behavior for Scottish center backs that was published in August, we looked at the total pass completion percentage and the percentage of passes attempted by a player that led to a shot to try and identify the center backs who are most involved in their club’s attack. We can do the same again for this the Premiership this season thanks to our partners at Ortec. As we did last year, we found the average for these metrics for every center back in the SPFL Premiership who has played at least 570 minutes so far. These averages were completing 79.38% of all passes and 0.68% of all passes attempted leading to a shot for a teammate.

We see some surprising names among those with the highest percentage of passes leading to a shot, with Declan Gallagher and Rickie Lamie of Livingston with the two highest figures in the league. This could be down to how Livi play, with the two often hitting direct passes. We see the two Livi center backs connect on the lowest and third lowest percentage of all their passes which could back up that hypothesis.


On the other end of the spectrum, four Celtic center backs in Kristoffer Ajer, Filip Benkovic, Jozo Simunovic, and Dedryk Boyata have completed the highest percentage of total passes but all have a lower % of passes leading to a shot than the league average. This stands to reason, as often times in the league Celtic’s opponents will sit off and try to stay organized and compact instead of pressing Celtic. This gives Celtic’s defenders time to pass around the back unimpeded but less opportunities to set up a teammate for a shot.

When we filter all that data, we see that there are only four center backs with above average figures for these two metrics. We see that Connor Goldson of Rangers, Darren McGregor of Hibernian, Dominic Ball of Aberdeen, and Jason Kerr of St. Johnstone. Now this is the part of the article where I repeat what I said about relying on numbers alone to scout players.

The big ugly stick analytics in football gets beat with often is that those championing the use of stats in football want to get rid of the “traditional scout” who “uses his eye”. Friends, this is a straw man. No one seriously dealing with football analytics would ever suggest such things. However, these numbers can help you find the proverbial needle in the proverbial haystack in filtering down a list of players if you know the characteristics of a player you would like to find. If you are looking for ball playing center backs, these four have the best metrics in the SPFL Premiership thus far.

Not every team needs a ball playing center back in the SPFL Premiership though. Many clubs in the league would be more than content with a no-nonsense defender. Someone who is good in the air, can win a tackle, and win the ball back is hard enough to find for some teams, so complicating things by requiring them to be able to start attacks and create chances for their team is not required. While there can be a bit of subjectivity when it comes to assessing defensive skill, again we can use stats to help filter players to find ones that meet the skill set we are looking for.

Defending Metrics for SPFL Premiership Center Backs. Showing the % of Aerial and Ground Duels won. Despite what she says, size matters here as the larger the plot is the higher the player’s possession regains per 90 are.  Interactive version here .

Defending Metrics for SPFL Premiership Center Backs. Showing the % of Aerial and Ground Duels won. Despite what she says, size matters here as the larger the plot is the higher the player’s possession regains per 90 are. Interactive version here.

Using the same group of SPFL Premiership Center Backs who have appeared in at least 570 minutes this season, we can find the average aerial duel win %, ground duel win %, and possession regains per 90 for this population of players. The averages for these metrics are 72.26% aerial duels won, 61.65% of ground duels won, and 8.10 possession regains per 90. There are eight players who are above all three of these averages in the Premiership. These are Filip Benkovic of Celtic, Gareth McAuley of Rangers, Michael Devlin of Aberdeen, Matthew Kilgallon of Hamilton, Stuart Findlay of Kilmarnock, Christophe Berra of Hearts, Joe Shaughessy and Jason Kerr of St. Johnstone.

Now you are an astute and wise football fan, after all you are on modernfitba.com. Surely someone so attentive and smart (and did I mention good looking as well?) noticed right away there is only one center back playing in the Premiership that appeared in both our queries looking for above average passing and defending stats. Yes, wise reader, Jason Kerr of St. Johnstone was indeed the only player to be above the league average for a center back in the SPFL Premiership.

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This season Kerr and Joe Shaughnessy have formed an impressive partnership in the St. Johnstone back line. Both have already appeared in over 2,200 minutes in league play, anchoring the defense of a Saints team that yet again aiming to finish in the top 6 or higher in the table. Looking at the graphs inspired by the work of our own Jason of The Rangers Report fame, we see the two have strengths and weaknesses that play well off each other. Though Jason Kerr still is above league average in the defending metrics we examined earlier Shaughnessy has slightly better numbers in these categories, while Kerr seems to be the superior player in passing the ball.

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Jason Kerr’s form this season in the back line of St. Johnstone has started to get noticed by fans and pundits alike. These observations confirm the statistics we have examined today, which is always reassuring when you are dealing with stats. Kerr is only 22 years old, so there is plenty of time to see further improvement from the Scottish center back. He has earned 5 U21 caps from Scotland and if he can continue the form he has shown this season, could a full cap be in the future?

Even a few years ago, many in the football stats community were unsure of how to use data to asses a defender. Now there is brilliant work that can quantify just how successful a club’s defenders are. We looked at numbers today that can help identify who would be best to play the style your team need. We are working hard and hoping to share soon a method of quantifying how many points a defender or any player on the pitch has earned their club.