One of the accepted nuances of elite-level sports, particularly football, is that teams and individuals perform better at home than away.
Academics have called it 'home-field advantage'. Teams — with a particularly strong effect for weaker teams — win and score more, lose less, concede fewer and keep possession more at home than away.
Plenty of that is true for Arsenal this season but, defensively, they have been significantly better away from the Emirates.
Mikel Arteta's side won 2-0 against Newcastle United last weekend, their 13th clean sheet of the season but, quirkily, 10 have been away from home. Aaron Ramsdale is only the third goalkeeper (after Petr Cech, formerly of Arsenal and Chelsea, and Manchester City's Ederson) to reach double digits in away clean sheets in a single Premier League season.
For all their early-season success, Arsenal only kept one home league clean sheet in their first six home games before the World Cup break. They had six in their first eight away trips.
This can be viewed as a good thing (lots of away clean sheets) or a bad thing (not many home clean sheets) depending on your outlook. But step back to look at the bigger picture and it is fairly neutral. Arsenal rank joint third, with Chelsea, for total goals conceded (39), third for expected goals against (39.2, behind Manchester City and Newcastle) and joint second for clean sheets (13, with Newcastle and Liverpool).
Sir Alex Ferguson's famous “attack wins you games, defence wins you titles” mantra feels particularly applicable.
Clean sheets are outcome (goal)-focused and will not offer clear insight for long-term success. You can keep clean sheets in different ways: Arsenal conceded just one shot at Leicester in the 1-0 win in February, whereas Ramsdale made seven saves in the 2-0 win at Tottenham, a game in which Arsenal conceded 17 shots.
Game state and its impact on style
Expanding on home-field advantage, Arsenal have less possession away than at home (by a margin of more than eight per cent) — fairly normal.
Game state is a partial explanation. Arsenal score earlier in away games, which simply means they have a greater opportunity to sit back and defend a lead.
Arteta's side have spent the majority of away games (55 per cent) in winning situations, the most of any Premier League team, and just 32 per cent of the time drawing. At home, those figures look different: four teams have spent more time in a winning position during home games, with Arsenal ahead for 14 per cent less of the time than they are on the road, drawing 44 per cent of the time. That's 12 per cent more than in away games.
Scoring and leading earlier means Arsenal can defend out of an organised block for longer, sitting deeper and dropping the wingers down to restrict central space, but also be in a position to play on the counter-attack. “Just realising that sometimes you can't just play beautiful football, sometimes you need to adapt,” said Jorginho after the win at Newcastle.
Arsenal's super-strength is their wingers, with speed, directness and quality in one-vs-one situations, which is better facilitated by moments of transition and attacking against disorganised defences/a high line than against a low block.
There have been smart match-specific tweaks, too. Away to Fulham, when Arsenal went 3-0 up by half-time, they pressed out of a 4-1-4-1, man-marking Fulham's central midfielders (yellow dots).
And in the north London derby win at Tottenham Hotspur, Bukayo Saka would often drop deep to make a back five against their opponent's 3-4-3.
Arsenal have less possession, but also press less intensely as an away side, making fewer high turnovers — defined as open-play possessions starting within 40 metres of the opposition goal — but defending their own box better.
There is a perennial trade-off that pressing can prevent opponents from building up and become a method of chance creation, but if it goes wrong then space is vacated close to a team's own goal and it becomes easier to play through them.
Similarly, Arsenal are more vulnerable to counter-attacks at home, as playing expansively in their typical 3-2-5 commits bodies forward.
Opponents are accurate with over 50 per cent of shots against Arsenal at the Emirates, compared to marginally over one-third shot accuracy in their away games. Arteta's side concede chances more often in away games and have less of the ball, but concede higher-quality chances at home, which are more likely, individually, to lead to goals.
This is a perfect representation of risk and reward, though interestingly, Arsenal's overall rate of goals conceded falls almost perfectly in line with their expected goals against. They are just under-performing at home to the same degree that they are over-performing away.
Success, errors and set pieces
Systems and approaches aside, individual brilliance and mistakes have played a part.
Ramsdale ranks third among Premier League goalkeepers for goals prevented (4.5) in away games, but is the third-worst at home, conceding 4.2 goals more than expected.
Ramsdale won Premier League save of the month for March (home to Bournemouth) and April (away to Liverpool), with the types of shots saved a reflection of Arsenal's home and away approaches. “The technical skill between the two is completely different,” the goalkeeper said.
His save to keep out Mohamed Salah's curler at Anfield is a tip around the post, unsighted from a shot on the angle from distance, with Arsenal defending in a low block.
The save at home to Bournemouth — with Arsenal 1-0 down inside the opening seconds to a kick-off routine goal — is also reflective of the transitional chances Arsenal are predisposed to concede more at home. At the start of May, Ramsdale did not rank in the top 10 Premier League goalkeepers for performance in one-vs-ones.
Arsenal conceded penalty goals at home to West Ham — a failure to defend a long pass in behind — and against Tottenham — a foul by Gabriel after Granit Xhaka tried to build short following a regain in his own penalty area.
Arsenal won both games 3-1 and, without these errors, they would likely have another two clean sheets (and this article might never exist), but there is perhaps weight to the theory that Arsenal defend better in away games because they spend more time defending.
Of their five errors leading to goals, four have been at home. Three of them were the opening goal of the game.
The most recent was at home to Southampton inside the first minute, as Carlos Alcaraz pounces on Ramsdale's attempted pass to Oleksandr Zinchenko.
Arsenal take fewer of these risks in away games, by virtue of being ahead more but also a common defend-first approach.
There was an error for the opening goal of the game against Fulham, one of eight home games in which Arsenal have conceded once. “We were in total control of the game, we made a huge individual error that cost us a goal,” Arteta said afterwards.
Even with Fulham's man-marking, Bukayo Saka switches play to Gabriel.
His first touch should go left or forwards, away from the direction of Aleksandar Mitrovic's press, but he gets the ball stuck under his feet and is tackled by the Serbian, who scores.
The most significant error was in the 3-1 home loss to Manchester City but is further reflective of Arsenal's different approach at home. They press higher and have more possession in home games, therefore opponents will predictably play long at times to push them back and avoid playing into their traps.
Ederson's long pass came about after City had initially tried to play through the thirds but were forced back to their goalkeeper, who kicked long towards Erling Haaland.
Takehiro Tomiyasu recovers the ball and attempts to recycle play back to Ramsdale. But he miskicks, and Kevin De Bruyne latches on, lobbing the goalkeeper.
Set pieces have been an Emirates Achilles heel for Arsenal — six of their eight set-piece goals conceded have been at home. Three of those (Brentford, Aston Villa and Crystal Palace), were the only goal they conceded in that game.
“We are conceding some set plays, we are conceding a lot in games,” said Arteta in March, before Arsenal's 3-0 away win against Fulham.
“We conceded two goals against Bournemouth and against Sporting (Lisbon in the Europa League). If you want to be at the top, winning and winning and winning, you need clean sheets.
“We've been really good at preventing chances but not good enough in the last two weeks, and doing the right things in the box.”
Arsenal have conceded almost twice as many corners in away games (82) as at home (42), but are conceding chances at a worryingly similar rate (28 set-piece shots conceded in away games; 24 at home). It is difficult to imagine anything innate about the Emirates that makes it difficult to defend set pieces there. Perhaps opponents put more stock or practice into their routines given Arsenal's ball dominance at home, knowing it might be one of their only means of scoring.
Next up for Arsenal is Roberto De Zerbi's Brighton & Hove Albion, who have scored 25 goals in 16 Premier League away games since the Italian's arrival, only failing to find the net once (against Brentford) in that time.
Regardless of how you microanalyse Arsenal's defence, it has evolved significantly this season, already matching last season's total of 13 clean sheets with three games to spare. Keep one more and it will be Arsenal's best campaign for shutting out opponents since 18 in 2015-16 under Arsene Wenger.