Lennon and Rodgers In Europe - An Expected Goals Adventure

Article by James Dailey

As I consume mainstream and fan-based Celtic-related media, I am constantly bombarded by “conventional wisdom” and provided with topics to analyze. Today’s subject is the often-repeated notion that Neil Lennon is a better and more pragmatic tactical manager than Brendan Rodgers- particularly in Europe.

I believe much of this notion is based upon the few absolute doings Celtic suffered in the Champions League under Rodgers – particularly 7-0 to Barcelona and 7-1 to PSG. Ultimately, games are determined by goals, but underlying performance metrics can help assess the balance of play and volume/quality of chances created.

All four results show Team A posting a dominant underlying performance advantage. For further perspective, Celtic has averaged an xG of 2.34 per game in the SPFL this season and scored 2.75 goals per game, while conceding 0.65 xG per game and 0.65 per game. Their highest xG in a league game this season is 4.33.

Before I come back to the four games listed above, let’s review aggregate Europa League group performances and compare this season’s campaign with last:

Celtic’s underlying group performance was significantly better last season. Despite the great results versus Lazio, we lost the xG battle by 1.87 to 3.31 in the two games collectively.

With underlying stats indicating Celtic played better overall last season versus this season, a logical question to ask is “why”? As I sought out an explanation, I immediately went to The Wall for answers.

Next is the xG conceded by campaign vs actual goals conceded for each group stage:

We can see that last season’s Europa League group stage essentially matched xG conceded. This season saw a 1.80 goal difference in our favor, but even that is deceiving relative to the impact of Forster, as he did not play in the last game at Cluj. Gordon conceded 2 goals that game on 1.93 in xG. If we look at just the 5 games with Forster in goal, he conceded just 4 goals on 5.87 xG conceded.

Given the sample size of these games, this disparity could be noise, but the disparity with Forster in goal certainly matches the “eye test.” Also, if we look at goals conceded vs xG conceded in the Champions League and Europa League qualifiers this season with Bain in goal, he surrendered 8 goals on an xG conceded of 6.64.

What would Rodgers’ Celtic have accomplished in last season’s Europa League group stage with Forster in goal or Lennon’s this season with Bain or Gordon? What would Lennon’s 2012 team have achieved in Europe with a Bain/Gordon level keeper instead of Forster?

Now time to reveal the mystery games:

The first Rangers result and data is from the League Cup final in December, and second from the first derby in Rodgers’ first season.

Managers sure do look smarter when they have a world class keeper.