I recommend you read this appreciation of Sergio Busquets, the great Barcelona and Spain midfielder, who will leave the club after a storied and trophy-laden career at the end of the season.

The article made me think about Celtic’s own pivot, Callum McGregor. Let’s be clear, Busquets is considered one of the greatest midfielders of his generation. I am not suggesting McGregor is his equal. However, he performs a similar role to the Catalonian within the Celtic midfield, and the following resonated:

"Not that it’s about the numbers; Busquets is almost the anti-stat, the footballer who can’t be measured or so easily deciphered. He had begun as a forward, coming on to score on his debut for Barcelona B but as a senior player he didn’t dribble, didn’t score goals – 20 in total – and didn’t provide assists.

"He was a defensive midfielder who didn’t "defend": he was not all heroic tackles, preferring to step out than dive in. He wasn’t a great athlete, or didn’t look like one. He didn’t cover countless kilometres and he didn’t move fast. The ball did, though, when it was supposed to. And when it was supposed to slow, it did that too. So did his mind. Busquets just knew. He saw."

What triggered this was a discussion with a friend about non-measurable assets like leadership and the limitations of data.

When I consider McGregor’s utility to the team I inevitably turn to the data, and here the echoes with Busquets are clear.

Being There

Normally with the captain, an undervalued but essential element is simply that he is there. Always. His robustness and minutes accumulated for club and country is the stuff of legend – the hardest-working player in world football by minutes played over the last few years.

Do not underestimate that. Managers love players who they can rely on to be fit and available. It builds trust. This season though, McGregor suffered a knee injury trying desperately to atone for an error away to RB Leipzig in the Champions League. The subsequent absence means he is fourth on the appearance chart, one he normally dominates.

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Prior to this he made at least 46 appearances over the last six campaigns and in total he has over 400 club appearances.

The Curse of Jack

As regards the performance data, to use the phrase “jack of all trades” is often a backhanded compliment. Is that fair or indeed accurate?

McGregor is not the most active player on the pitch. With a 73.92 possession event per game, he would be ranked ninth by those criteria, and with 68.11 open play passes completed, the fourth highest in the squad.

He is a defensive midfielder, nominally, so has he got the best defensive stats?

With a 57 per cent defensive action success rate and 71 per cent possession won from defensive actions, he is certainly the most defensively efficient of the midfielders. But as Roy Keane would say, “That’s his job!”.

Scott Brown would average 64 per cent and 77 per cent, respectively, for the same metrics. So he has not replaced the former captain's destructive reliability?

But he is a great passer, right? Well, he is accurate. 92 per cent of his passes in open play hit the mark, the best of the non-defenders. But his packing pass score of 49.27 is bettered by Aaron Mooy and all the defenders apart from Cameron Carter-Vickers.

McGregor is a great ball carrier but if we consider he provides that service in the opposition half 1.81 times per 90 minutes, that only ranks 14th in the squad.

His secondary assist rate (a key metric for deeper midfielders) of 1.35 per 90 minutes is 11th best in the squad. As regards more direct assisting, he provides 1.21 chances from open play which ranks 14th overall.

And as a goal threat, although McGregor is at 60 Celtic goals, they have dried up slightly in recent times, and his xG per 90 minutes is a mere 0.07. Even Carl Starfelt (0.09) is higher.

I could go on. I have over 200 per 90-minute metrics per player and I’d be hard pushed to find anywhere McGregor ranks first or second.

Celtic Way:

Yet we know with our eyes how important McGregor is to Celtic and instinctively see value in the way he seems to knit the team together.

The Black Box

Something that is fascinating is StatsBomb’s On Ball Value concept, although it is a heavily aggregated metric using proprietary algorithms and, therefore, difficult to interpret as to why a value is what it is.

And, like the event data, it does seem to be a bit “meh” when it comes to McGregor.

It likes his passing a bit. Defensive action, ok. Hates his shooting (I’d agree with this) and is decidedly average about his ability to dribble and carry the ball.

An overall OBV of the 64th percentile is not what you’d expect for Scotland’s premier midfielder and someone who was voted by his fellow pros as a Player of the Year contendeder.

Imponderables

I would never claim the event stats capture all the relevant data about football, in fact I’d insist it doesn’t. The analogy I always use is that football data is like counting stars. We see the bright shiny things. We do not recognise all the planets nor what happens in the seemingly black space in between.

Especially off the ball, without Global Positioning Software / tracking data the lay analyst has no feasible means of measuring movements without the ball. Remember, a player will have possession of the football for around 90 seconds a game. So that is a lot of black space.

And then there is the importance of non-technical attributes like leadership and influence. My own opinion is that these are hugely overstated as to the positive influence they can make on performance. I’d further clarify to say that the absence of such attributes would likely have a more discernible negative effect.

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I do not believe that the quality of Celtic’s on field performance as a team hinges on the quality of McGregor’s pre-match huddle speech. It is important he does it, and the absence of it might slightly dent morale, but does it help Starfelt head the ball straighter in the 75th minute? Unlikely.

Defining McGregor. Back to the captain. And back to Busquets. 

What McGregor brings that the data cannot capture is his ability to pass and move at a speed that is variable depending on the demands of the game and in a way that provides a platform for the other more attacking players to express themselves. 

He also provides the outlet for the defenders to progress the ball. That might be simply dropping into the back three or shifting wide, allowing a full-back to take the central inverted space.

Sid Lowe describes the Spaniard thus: “That piece upon which it all hinges, a player for whom pace is in the mind, something to be imposed upon the ball: who knows when to apply a pause, when to hold on and above all when to release. Who quietly makes everything else work around him."

In the absence of corroborating data, we are back to the art of interpreting space and time and manipulating the ball around the team in concert with the needs of the moment.

Timing is everything. It is not the volume of activity, it is when it occurred and it’s value in that moment. 

“Pivot” sounds almost demeaning.