The Celtic Creatives with Alan Morrison: Assist Kings

We need to see creativity as an aspect of play for all 11 players. Various metrics allow us to establish who progresses the ball from deep most effectively, mainly through passing but sometimes through running with the ball at feet.

Different data points help us assess which players are getting the ball into good positions from which there is the potential to create chances.

You can read parts one and two at your leisure. For now, you will be pleased to hear, we move on to actual chance creation...

Secondary assists

There are analysis metrics that chain together all passes in a move and assign each pass the xG of the shot eventually taken. 

There are other more complex models that attempt to assign a specific xG value to every pass in terms of what 'threat' it added to an attack.

For simplicity, we can capture the pass before the pass that creates the shooting chance and that is known as the secondary assist. Some call it the establishing pass.

This is an indicator of the ability to create time and space for a teammate such that a chance can be provided for the team.

For example a through ball from Matt O’Riley to the advancing full-back Anthony Ralston who, without breaking stride, can get a cross in that allows a header at goal from Giorgos Giakoumakis. We assign the provider of the through ball (O’Riley) the xG value of the chance created as their secondary assist xA.

Here is the view of secondary assist volume (number of secondary assists contributed per 90 minutes) and quality (xA value of those secondary assisting passes):

Given the fluid nature of going back a pass before the creating pass, this distribution is slightly less position-specific.

The central midfielders - who, in Ange Postecoglou’s system, push up high, sometimes very wide and sometimes beyond the striker - dominate the top end though. 

David Turnbull in particular stands out and Aaron Mooy is not far behind. Reo Hatate has a lower quantity of secondary assisting passes but higher quality as measured by xA. 

Ralston stands out amongst the full-backs in terms of volume and Greg Taylor in terms of quality. This could be because many of the right-back's balls into the box are high crosses while Taylor’s tend to be low cutbacks. A low pass to feet is, in general, easier to manipulate than a lofted ball.

The winger distribution is fascinating. Sead Haksabanovic has been prominent in all the creativity metrics and is on his own at the top of the chart for both the volume and quality of passes he provides leading to chances.

Liel Abada is not far behind with the biggest surprise perhaps being Jota profiling more like a centre-back in terms of secondary assists. That will likely change when we look at assisting passes.

Open-play chance creation

Finally, we come to those that provide the killer pass to set up a chance. 

But, of course, it is often not a clinical pass. Rolling the ball to someone on the halfway line who then runs forwards 50 yards and shoots into the top corner is also considered an assist / assisting pass. 

So there is quite a bit of noise in assist data which is why expected assists (xA) is far more insightful and should best be consumed in high volumes (i.e. using a large sample size).

First we will consider chances created from open play, as set piece-taking is a specialist skill. 

The interpretation of 'assist' here is the original Fantasy Football definition; a far broader concept than what appears to be conventional in the SPFL by Opta or StatsBomb.

For instance, these data providers exclude a player being brought down for a penalty as an assist. Here, that counts as an assist while winning a free-kick that is then scored is included on the same principle.

Additionally, the logic here is that even if the ball is touched by an opponent on its way to the scorer, provided the ball has not changed direction, the assist is still awarded. 

Emerging from that rabbit hole, let’s take a look at the expected assist data:

Once again there is normal clustering by position and we can discount both the centre-backs and strikers from this analysis as, in Postecoglou’s system, those players are not necessarily expected to provide this function. 

Of the full-backs, while Ralston and Taylor provide the highest volume of such passes, it is Josip Juranovic who has the slightly higher chance created quality off his assisting passes.

In midfield, O’Riley’s numbers have fallen back to be comparable with Callum McGregor’s due to the demands of the number six position.

We see that Hatate provides far fewer of these types of passes than the other regular number eights. This is consistent with what was observed last season and, while his high-risk brand of passing can sometimes open up defences spectacularly, he would benefit from a slight adjustment in his range to deliver better quality with fewer passes turned over. 

Mooy and Turnbull have very similar numbers and O’Riley will likely be around their level when he returns to the eight position. The Australian and the former Motherwell man do not, perhaps, receive the fanfare of other attacking players and this is why metrics such as expected assists are useful in highlighting the utility of players like them.

As regards the attacking wide players, Jota is in his own little island where we perhaps expected him but Haksabanovic, as signposted after relatively few appearances, does post good numbers.

Abada’s worth, often hidden under some poor decision-making, again is highlighted and he consistently produces in the final third.

Daizan Maeda is interesting in that he does not produce many assisting passes but, when he does, they tend to be high-quality chances. James Forrest’s role as a backup in his veteran years is further exemplified in this data.

Set-play chance creation

For completeness, here are the numbers for those who primarily take set-pieces (corners and free-kicks). Those included are the players who have more than zero assisting passes or expected assists from set-play passes.

Note also that Celtic, being a relatively small side in terms of height, do not often put high balls into the box from corners and free-kicks. There is variety in Celtic’s corner routines to compensate (credit Gavin Strachan and the fabled laptop).

Corners tend to be taken quickly and short, therefore the volume of direct chance creation from such situations is low.

All that being said, it is no surprise Turnbull is the most productive chance creator in terms of both quantity and quality from these situations.

If Celtic revert to a Martin O’Neill-type side with five or six players well over six feet tall, the 23-year-old's set-play stats would likely need a new scale all to himself. 

Summary

Through the various aspects of creativity, we can see how all members of the squad contributed.

The centre-backs need to break the initial opposition press or block and Stephen Welsh in particular shows up well in this regard.

Jota and Haksabanovic are the most capable of getting balls into dangerous areas central to the goal. 

They also create the most direct opportunities for shots. Turnbull is Celtic’s set-piece specialist but what is really highlighted from this series of analyses is the corporate nature of these skill-sets.

Creativity is not the preserve of some magical number 10 around which the other players are in thrall, it requires skills throughout the team.

READ MORE FROM THIS AUTHOR:

• The Celtic Creatives Part 1: The Ball Progressors
• The Celtic Creatives Part 2: Get it in the mixer!
• Do Celtic have a penalty problem?