Is Celtic's number one right-back really who you think it is?

I wrote a while back that it would be difficult for Josip Juranovic to match the level of production Anthony Ralston offered while he was the first-choice right-back; this column will take a fresh look at that argument with the benefit some new evidence to consider. 

First, a little caveat: it is difficult to disaggregate StatsBomb data, so the samples used will not be pure.

For example, some of the performance data for Juranovic will include a small number of minutes at left-back, and the team-level reports include Sunday's game against Livingston as part of the ‘Juranovic sample'. 

For these reports, the Juranovic sample starts when it appeared he assumed the position as primary right-back - that is to say, starting with the December 2 fixture versus Hearts.

The radars show Ralston for the entire season versus Juranovic since that game, with the first focused upon On-Ball Value (OBV):

We can see from this radar that Juranovic has indeed had difficulty matching Ralston’s performance output, with his OBV coming in at almost half his team-mate's. However, this is not to suggest Juranovic has performed poorly at right-back. 

Next, let's take a look at metrics which contribute to the output measured by StatsBomb's Pass and Defensive Action OBV:

These offer additional context as to the level at which Ralston has offered attacking output, and how much higher it has been versus Juranovic to date.

It also suggests Ralston has been less secure on the ball, with his rates for turnovers and dispossessions far higher.

From a defending and pressing perspective, the radar shows what we may expect given the relative parity in Defensive Action OBV – they are generally pretty similar, with Juranovic seemingly being more efficient. 

Obviously, the two players do not perform in a vacuum, so how has the team performed over these two periods?

The two radars show that the periods comprised almost half the season so far, and how similar performance levels have been.

The major differences in the OBV radar over the periods were Goalkeeper OBV both for and against, as well as a sharp decline in Shot OBV from opposing teams. Generally speaking, it is difficult to see how the participation of Ralston over Juranovic, or vice-versa, would meaningfully impact either metric.

Next, we have a look at how their primary partner at right wing, Liel Abada, has fared during the two periods:

Here we can see that Abada’s Pass and Dribbles & Carry OBV metrics dropped while playing largely with Juranovic, with his Defensive Action OBV higher. An aggregate of those three metrics show a decline of about 40 per cent (0.40 vs 0.24) during the Juranovic sample. 

The main difference in considering all this information appears to be the productive distribution between the right wing and full-back positions, with overall output having been comparable.

This speaks to the importance of the playing style and system, as well as having quality depth with which Ange Postecoglou can tweak things in order to accentuate player strengths and protect against weaknesses while also rotating players.

In other words, as was apparent in Sunday’s impressive victory over Livingston, the manager has various good selection options from which to decide.