Arsenal, Liverpool ,Big Chances & flaky defences

In football, goals win you matches. But not conceding goals, or defense, wins you titles. Or so the saying goes. Of course, this is backed up by strong evidence. While Leicester’s fairy-tale win last year was credited to the goal-scoring exploits of Jamie Vardy and the creative output of Riyad Mahrez, their charge to the title picked up steam only when they started to keep clean sheets in the latter part of the season. With N’Golo Kante sweeping up everything in front of them, the centre back pairing of Wes Morgan & Robert Huth looked like world-class defenders.

In the end, Leicester finished with the second best defensive record in the league. This season, too, Chelsea’s domination in the league has been built on a robust defence(they have conceded 25 goals in 31 games; only Tottenham Hotspur have conceded fewer).

One of the reason frequently cited for Arsenal not winning the title is their *porous* defence. Whilst Arsenal have once again become an extremely open side this season, it is quite ironic that it was their attack that let them down last season in what was their best chance to end the Premier League drought. As Ted Knutson explains in this Statsbomb piece, Arsenal under-performed vis-a-vis their xG numbers last season & Colin Trainor looked at the number of Big Chances missed by Arsenal’s attackers with Ramsey, Alexis & Walcott particularly guilty. Also, the aforementioned StatsBomb piece points out how Arsenal after two seasons of excellent defensive output — which entailed a slightly passive defensive “structure” whose aim was to allow as few clear cut chances as possible — have slipped back to the bad habits of 2011–12 to 2013–14.

Arsenal’s exceptional Big Chance Numbers

Replicating the same chart for this season, produces some interesting insights.

Net Big Chances 2016–17 Premier League -> Liverpool & Arsenal highlighted in red

While the most noticeable thing comparing the two charts is how badly Arsenal have fared compared to last season, it is surprising to see Liverpool below Everton & just above Arsenal. In December, I had written about how Arsenal needed to tighten their defence having conceded 27 big chances from 17 games. In contrast, Liverpool were up there with Manchester City, Tottenham & United as one of the best defensive teams in the league(conceding about 1.1 big chance per game).

I also noted how Arsenal’s defense at home was extremely flaky with only Hull conceding more “Big Chances” than the Gunners. Only poor conversion from the opposition & their own ability to create more than the other team was bailing them out. Liverpool in contrast allowed very few clear-cut/big chances at Anfield.

Before the latest round of Premier League matches, this is how the Big Chances Conceded table looked:

Last column indicates Big Chances Conceded per game

While Arsenal have not stopped leaking big chances & goals, Liverpool’s defence has been quite brittle since the New Year. The thing to note is how bad both defences are compared to the other Top6 clubs(highlighted in yellow).

A look at the same Big Chances Conceded table for the last 15 Premier League match days shows Liverpool’s struggles in preventing opponents from creating clear-cut chances.

Premeir League 2016–17 Avg. Big Chances Conceded from Game17 to Game32

While Arsenal are conceding at ,more or less, the same rate(close to 1.5 Big Chances per game), Liverpool over their last 15 games have conceded 30 Big Chances of which 16 have been scored. Also, notice the skew in Arsenal’s numbers. Out of the 19 Big Chances they have conceded in the last 13 games, 14 have led to goals. Whilst it is not prudent to draw any conclusions based on such small numbers, the Gunners might be victims of a bit of random variation.

That said, Arsenal’s structural deficiencies are a much bigger issue than Liverpool’s defensive issues which seem to be arising out of individual defenders’ quality, or lack thereof. Liverpool’s problems can, probably, be solved in the transfer market. On the other hand, Arsenal fans may have to look for divine intervention given that Wenger seems intent on staying put.

P.S:- Arsenal & Liverpool have made the most defensive errors leading to a shot in the last 5 seasons.

Courtesy of @BassTunedToRed