Arsene Wenger would have been sympathetic of Wigan Athletic's selection problems for this match, as last season the Arsenal boss was forced to field four centre-backs in a makeshift defence. On Saturday, Roberto Martinez had a surplus of full-backs, meaning his usual 3-4-3 formation was unlikely to feature.
Instead, the Wigan manager turned to a more orthodox four-man backline using Martin Figueroa and Emmerson Boyce in central defence. The defensive base of the side was easy to decipher, the rest less so, and the question of the Latics' formation was an intriguing one.
Was it 4-5-1, or was it closer to 4-1-2-1-2? A 4-3-3 would have done it justice, but none of those numbers really properly accounts for the contrasting movement from the wide players. Their role was key in what was a highly competitive performance from Wigan: Franco Di Santo made runs towards the penalty area from a right-wing position, while Shaun Maloney drifted inside into a pocket of space just behind Mikel Arteta.
That was crucial, as both sides were evenly matched in midfield, with James McArthur paying particular attention to the movement of Santi Cazorla. Therefore, it was three v three in the middle, but Maloney's narrow positioning gave his side an extra man, meaning they dominated possession for the majority of the match and could work the ball into good positions.
They were aided by a very confused pressing game from the away side -- sometimes Cazorla would drop alongside Wilshere, other times there was an unnecessary focus on keeping a good shape -- and Jack Wilshere's moment of obvious exasperation at Cazorla midway through the half summed up his side's lack of clarity. They may have been surprised by Wigan's rejigged formation considering the Latics have played 3-4-3 for the better part of the year, but whatever the reason, it gave their opponents to stamp their authority on the match.
David Jones was the biggest beneficiary of the midfield dominance - he finished the game with a 98% pass completion rate, although the majority of his passes was safe, sideways distribution from flank to flank, helping to bring the wide defenders higher up the pitch. Jean Beausejour and Ronnie Stam are naturally attacking full-backs but they were encouraged by the space created by the narrow movement of Wigan's wingers. They frequently received the ball in positions high up the pitch but the final ball was often horrifically inaccurate, something made even more disappointing by the fact that Kone and Di Santo are decent in the air.
The flipside of this ambition was that it gave Arsenal obvious areas to attack towards, and they had a notable focus towards their right, where Bacary Sagna motored forward in attack in support of Alex Oxlade-Chamberlain. The two combined for twenty-three passes, trying to overload the defensively suspect Beausejour who would have been used to defend higher up the pitch and with the cover of three defenders. To be fair, McArthur occasionally moved deep into that zone to help against Arsenal's threat, but with an astonishing 52% of their attack coming down that side, it was surprising that the Gunners didn't take greater advantage.
Wigan's frustration at their poor execution was quickly exacerbated when Theo Walcott won a penalty, unsurprisingly on the right, which Arteta duly converted. Wenger then resorted to his default strategy when defending a lead, which is to bring extra midfielders to help control possession in the closing minutes. He repeated his first sub against Reading last Tuesday when Aaron Ramsey came on for Oxlade-Chamberlain, then Francis Coquelin provided more security in the centre of the pitch when he replaced the quiet Lukas Podolski.
A combination of five central midfielders strung out across the width of the pitch and some desperate penalty-box defending ensured the result.