Is Signing Forster Necessary?

La Grand Muralla has returned to Celtic on a one-year loan deal - not official as I write but it looks like happening. What does Forster’s arrival mean for Bain and Gordon? Is it just injury cover, effectively replacing De Vries in the squad? Or are there grounds for Forster to push to take that number one jersey back?

The Undisputed Number One

Last end of season review I showed how, comprehensively, Bain had earned the number one shirt. You can review in The Undisputed Number One.

I look across a number of key metrics to show that Bain was making more saves, was saving shots of higher quality, and in addition was 8% higher on pass completion.

We know that the latter is not a priority for Lennon and the data shows Bain’s passing accuracy has fallen off the cliff – it is now 72% compared to 86% last season.

That is probably a team style conversation for another day.

This pre match short article will simply highlight two key goalkeeping metrics.

On Target Shots Saved

Let’s compare both ‘keepers last season tot his (remember very little data to go at this season):

Both incumbents have fallen off as regards the % of on target shots they are saving. Gordon was well behind Bain last season and his save % fell a further 2% this season.

Bain’s save % has collapsed from 85% to only 50% so far this season.

Goals Conceded vs xG

But as we know, if all you are saving is 40-yard trundlers, this doesn’t tell you the full story. We need to consider shot quality and hence the Expected Goal (xG) value of the shots on target.

What this shows is that in 18/19 Bain dealt with shots that had a per 90m xG of 0.616 but only conceded on average 0.37 goals. In other words, he saved more shots than could be expected given the shot quality.

But Gordon dealt with shots that would be expected to yield 0.741 goals per 90m, but actually conceded 0.84 goals per 90m. He was conceding more goals than expected.

This season has seen Bain face shots expected to yield 1.011 goals per 90m but is conceding 1.29 goals per 90m.

In Gordon’s two appearances, his xG against is 0.341 but he has conceded the equivalent of 0.43 goals per 90m.

So, both current Celtic ‘keepers are conceding more than expected. This may be as a result of lack of defensive cover of course. And we all know what a hot subject that is. Also, as mentioned, it is a very small data sample for this season.

But, using very simple metrics, it seems like Lennon could be right that the goalkeeping department needed strengthening.