Season Review: Centre-backs (Part 2)
Written by: Christian Wulff (@ahellofabeating)
In the first part of this season review of the Premiership’s centre-backs I analysed the overall defensive record of each team and how this was affected in different ways when the different players had been on the pitch.
This second part of the analysis will focus on the centre-backs’ individual stats: their actions with, and competing for, the ball.
It can be difficult to draw a direct correlation between the performance between such metrics and the player’s influence on their team’s defensive record, but it will tell us quite a bit about their individual actions on the pitch and their style of play. Note that these stats are only for when the players have played at centre-back (according to InStat) and don’t include actions when they were playing in other positions.
First of all, let’s see how ‘busy’ the different centre-backs have been:
The graph above show the amount of passes and ‘actions’ each player has made per 90 minutes played in the Premiership this season,. The term ‘actions’ includes all duels on the ground and in the air, dribbles and tackles attempted by a player, loose ball recoveries and dribbles.
With their team’s high amount of possession, it’s no surprise that four Celtic players have the most passes (five if including Hendry’s time there), with Liam Fontaine the busiest player when it comes to actions, averaging over 26 every 90 minutes.
The Motherwell players are all closely grouped below average when it comes to passes, a very distinct difference to Celtic.
Aaron Hughes stand out as a sore thumb: on average he is involved in three actions less per 90 minutes than the second least busy challenger, Jozo Simunovic. Hughes is not a specifically prolific passer either. Performing few actions on the ball doesn’t necessarily mean a worse performance by a centre-back, but Hughes is such an outliner you could be forgiven for wondering what he has been up to during his time on the pitch.
There are only three players who are above average when it comes to both passes and actions per game; Danny Wilson, Peter Hanlon and Kristoffer Ajer. While you would expect Ajer to be amongst the most prolific passers, he is also involved in significantly more actions than his Celtic teammates and as 12th overall in the league, he is one above a player such as Christoph Berra. It is the first of many data metrics that points towards the young Norwegian having a very unique skill-set, something that becomes even clearer over the next two graphs.
Today’s centre-backs are often – rather lazily – put into two main categories.
There’s the ‘traditional’ type; characterised by being strong in the air, winning challenges and enjoying getting stuck in with a tackle, while maybe being a bit more limited on the ball, happy to get it away from his feet as quickly as possible.
Then there’s the counterpart; the ‘modern’ centre-back, comfortable passing and keeping hold of the ball, happy to use his dribbling skill to both get out of defensive troubles and to go on offensive runs, while helping to set up chances for his team. The modern centre-back is often accused of lacking the toughness and grit of the more traditional type, perhaps shying away from a tackle and easily defeated when the challenges get tough.
Enter Kristoffer Ajer.
If you combine air and ground challenges + successful tackles, the Norwegian is second among all the centre-backs for win percentage rate, only Christoph Berra faring better in all these duels. If you look only at aerial challenges – maybe the strongest side to this perceived ‘traditional’ centre-back -he is third. At the same time, he has attempted the second most dribbles per every 90 minutes played and is also second in open play chance creation, both times only behind Efe Ambrose (graph below):
Ajer’s skillset is unique and not just within the league but also among his fellow Celtic centre-backs (with maybe one exception, more on that later). His numbers point towards having the potential to develop into the holy centre-back grail of today’s game; a player who has the qualities of both the ‘traditional’ and ‘modern’ centre-back, rolled into one physically intimidating package.
What about losing the ball in all these dribbles and offensive forays, I hear you interject. Well, his dribble success rate is 72% (Ambrose has 77%) and could be improved (although not bad), but when it comes to actually being disposed by an opponent through a tackle, guess what?
Yeah, he’s among the best there as well:
Ajer is fourth in the league when it comes to losing the ball in a tackle by an opponent. The three people above him, Aaron Hughes, Peter Hartley and Tom Aldred, are 21st, 39th and 37th respectively when it comes to attempted dribbles. These are safety-first centre-backs, compared to Ajer’s offensive and ball-playing outlook. Other big dribblers such as Efe Ambrose and Danny Wilson were losing the ball almost twice as many times as Ajer.
As mentioned at the start of this analysis, it’s very difficult to ‘rank’ centre-backs in any definitive way when it comes to stats. What we can say confidently based on these numbers is that Kristoffer Ajer is the most unique centre-back in the league. If you want to read an in-depth tactical analysis of Ajer’s playing style and how it might influence Celtic’s game in years to come, read this superb work by fellow Modern Fitba contributor Alex Lawrence, for the 90 Minute Cynic website.
So how unique is Ajer? Are there any centre-backs in the league that come close to his skill-set? Interestingly enough, there is definitely one player showing the potential to match him; his (almost) new teammate, Jack Hendry. If you look exclusively at his time at Dundee this season, Hendry is below Ajer when it comes to dribbles attempted, challenges + tackles won, being dispossessed and creating chances – but not by a huge distance and he is way above the league average in all categories. He has also done this in a far inferior team than Ajer.
Hendry’s stats from his Celtic appearances are actually quite different and not as good; he’s lost the ball a lot and won fewer challenges. But it is a much smaller sample and can be also be attributed to having a “phasing in” period with his new club – the Celtic team has also not played well overall in the games he has played.
The similarities to Ajer’s – very unique – skillset are there and it highlights the logic of Celtic’s purchase of Hendry in the January transfer window; Celtic now have two young centre-backs who, to various degrees, transcend the notion of being either a traditional or modern centre-half.
So what about the other teams and players in the individual stat categories? Let’s revisit the challenges + tackles won data:
Christophe Berra tops the league in challenges + tackles won. He is in many ways the quintessential traditional centre-back we’ve described before; his passing and dribbling attempts are well below average and so is his chance creation. That is fine, he is there to do a specific job and he does it mostly well. The real worry should the amount of times he is dispossessed, the 8th highest of the 40 centre-backs in this analysis.
His main partner, John Souttar, is pretty much the opposite; 10th in dribbles and 8th in chances created, he loses the ball less than Berra but he is 35th in the league when it comes to winning challenges. There is plenty of sense in trying to pair two significantly different types of centre-back such as Berra and Souttar, and it’s not that either of them are particular bad, but as a pairing their individual stats are the same as their team’s stats; just average. Hearts might have conceded the third fewest goals this season, but there are clear warning signs in the more advanced data; performances need to improve otherwise they will start conceding more goals next season.
The numbers are much more kind to John’s brother Harry. Only 19, he couldn’t stop Ross County from getting relegated but his loan spell from Stoke was quietly very impressive. Ross County’s team stats on chances conceded and chances created from the centre-back area was better than the league average when Souttar was on the pitch. He was 4th in challenges + tackles won and well above average in dribbles, chance creation and not being dispossessed on the ball. While not as wide a skillset as Ajer and Hendry, there are some similarities there. Number-wise, both on an individual and team level, he outperformed his brother and would be a very interesting option for pretty much any Premiership club next season.
Aberdeen and Motherwell were 2nd and 3rd when it came to the team rankings, and there are plenty of reasons to be found for this in the individual centre-back ratings.
Three of Motherwell’s centre-backs were above average in the win rate for challenges + tackles, with Tom Aldred not far behind. Only Charles Dunne lost the ball more than the league average, and all four had some of the best stats in the league when it came to their team restricting chances and chance creation when they were on the pitch. Cedric Kipre has been much lauded this season, and the stats confirm his good performance and great potential; together with Ajer, Hendry and Harry Souttar he is the only player above average in all the four categories of challenges + tackles won, dribbles attempted, dispossessed on ball and chances created. The average age of these four centre-backs is just above 21 years – it’s maybe not a coincidence that it is this new generation of who seem to best combine the qualities of the perceived ‘traditional’ and ‘modern’ centre-back type.
Aberdeen’s Scott McKenna had his breakthrough this season and he is a very good, no-nonsense type of centre-back, ranking 6th in challenges + tackles won (if you look only at tackles, he is first). Like his team, he mostly keeps it simple, attempting well below average amount of dribbles and -despite him scoring one of the goals of the season from long range – in setting up chances. He’s got a very good and similar partner in Anthony O’Connor, who is actually third in challenges + tackles won when he’s played at centre-back this season. To be frank, they are a lot better off without Kari Arnason, who scored considerably worse than his teammates in pretty much every single team and player ranking.
What about the worst performers? Dundee as a team had the worst defensive record this season, and the individual stats weren’t pretty for their centre-backs either, with the exception of the now departed Jack Hendry. While he was bottom of the league in team chances conceded from the centre-back area, Josh Meekings’ individual stats were far better than Steven Caulker and Darren O’Dea. Caulker did have a positive influence on Dundee restricting chances when he was on the pitch, but he is towards the bottom of the league in both win rate in challenges + tackles and losing the ball, with O’Dea only slightly better. He just missed the minutes played criteria for being a part of this analysis, but Kerr Waddell’s numbers were more promising when it came to winning challenges, especially in the air.
He has only been mentioned in passing so far, but Alexandros Gogic is a contender for the worst performing centre-back this season. He won the second fewest challenges + tackles (only ‘beaten’ by Kirk Broadfoot), he was 4th worst when it came to being dispossessed (while attempting very few dribbles), when he was on the pitch Hamilton was the second worst in the league when it came to conceding open play chances in the centre-back area and he was also towards the bottom in chances created from this area.
The most interesting thing about the Rangers centre-backs was the wide range between them, both in style of play and stat ranking. Danny Wilson was a very prolific dribbler while winning relatively few challenges + tackles, with Bruno Alves the complete opposite. They both lost the ball a lot more than the league average, and while Russell Martin did well in that category, he had one of the lowest win rates when it came to challenges + tackles. David Bates was somewhere in the middle of all the individual categories, and while he had good numbers on chances conceded when he was on the field, he was the worst Rangers performer when it come chances created from the same area. Alves and Wilson were the complete opposite in that regard, with Martin now right in the middle when it comes to the team rankings.
As with the team itself, there seems to be no clear identity among the Rangers centre-backs. On a whole, Bruno Alves might be said to be their top performer, especially based on having the 7th best win % in challenges + tackles (he was 1st in air challenges), although David Bates did show a lot of promise overall.
A special mention most go to Efe Ambrose for continuing to be Efe Ambrose; as a centre-back he dribbled far more than anybody else and set up the most chances from open play, while also losing the ball a lot and being among the worst in the league when it came to winning challenges + tackles. Never change, Efe.
The above is the currently the most advanced defensive stats we have available for Scottish football and it is a lot more detailed and useful than we’ve ever had before. Even so, it is more difficult to draw certain conclusions about centre-back than any other positions. As always with numbers, they need to be seen in context of a much wider analysis of a player.
They have at least giving us some specific things to look out for next season:
Hearts will likely concede more goals unless they can restrict the amount of chances they concede.
In McKenna and O’Connor, Aberdeen have a very solid centre-back pairing who will be very hard to play against.
There are big question marks over Steven Caulker, and Neil McCann should start easing out Darren O’Dea in favour of Kerr Waddell.
Motherwell have four very consistent centre-backs, and are likely to concede less goals next season if they keep this same level of performance up. If Cedric Kipre can continue his upward trend, he will be a very interesting target for many bigger clubs.
Whatever Steven Gerrard’s plans are for next season, he lost a good alternative in David Bates, while Russell Martin is definitely not the answer.
Harry Souttar would be a great buy – or loan signing – for any team in the Premiership.
In Kristoffer Ajer and Jack Hendry Celtic have a potentially very unique and exciting centre-back pairing for years to come.
In the end, Kristoffer Ajer is the stand-out centre-back in the Premiership. He has only just turned 20, with really just over one full season of centre-back performances behind him, spread over two different clubs. He still needs to develop many aspects of his game, especially his decision-making in when to dribble and when to commit to tackles.
Under Brendan Rodgers at Celtic, and with an experienced centre-back such as Kolo Toure working directly with him, he is also in the perfect place for that development to be realised. Next season he is likely to play a lot more games in Europe and together with an extreme maturity and clear leadership qualities, his unique skill-set of ‘traditional’ and ‘modern’ qualities makes him the most exciting centre-back prospects in the Premiership, certain to attract interest from all over Europe.