Alexis Sanchez rightly took the plaudits for his delightful hat-trick in Saturday’s 1-5 victory at West Ham.

The Chilean forward earlier unselfishly lay on a tap-in for partner in crime Mesut Özil to open the scoring. However, Saturday’s victory owed a lot to tactical tweaks which have brought the best out of Arsenal’s other goalscorer, Alex Oxlade-Chamberlain.

Between Watford and Spurs, Arsenal played a hybrid formation, which closest resembled 4-2-3-1. Against Bournemouth and West Ham, the formation closer resembled a 4-4-1-1.

Oxlade-Chamberlain is the player who has most benefited from this shift.

He’s a more direct and less patient player than Alex Iwobi, who he has replaced. Iwobi’s game is about drifting and receiving the ball in pockets of space. At the start of the season, he helped take the creative burden off Özil and provided a foil to enable the naturally goal-thirsty game of Alexis and Theo Walcott.

Iwobi was crucial to the way Arsenal set out to play as there was no other player in the squad capable of doing his exact job as well as he did.

LONDON, ENGLAND - DECEMBER 03: Alex Oxlade-Chamberlain of Arsenal celebrates with team mate Granit Xhaka after scoring his team's fourth goal during the Premier League match between West Ham United and Arsenal at London Stadium on December 3, 2016 in London, England. (Photo by Jordan Mansfield/Getty Images)
LONDON, ENGLAND – DECEMBER 03: Alex Oxlade-Chamberlain of Arsenal celebrates with team mate Granit Xhaka after scoring his team’s fourth goal during the Premier League match between West Ham United and Arsenal at London Stadium on December 3, 2016 in London, England. (Photo by Jordan Mansfield/Getty Images)

Iwobi’s game helped Arsenal when they were playing possession football and looking to retain the ball in the opposition half to break down defences. He was also another player capable of playing a telling pass that defences had to respect, rather than focusing all their attention on Özil, as had been the case for much of the second half of a frustrating 2015/16.

As the season has gone on, Alexis has grown into his new role as Arsenal’s false nine.

He drops deeper and assumes some of the creative burden. To counterbalance this, Özil alternates with Walcott in making runs into the space Alexis has vacated. With Alexis and Özil growing in their new dual threat roles, the need for a functioning Iwobi lessened. Following a recent dip in form, Wenger considered switching it up tactically and bringing someone else in to do a different job.

The Ox is a different player to Iwobi.

Rather than being an enabler who facilitates the game of others, he is a high risk, high reward player, who looks to take players on and beat them himself. He’ll make things happen, but also sometimes try too hard to do this and make a bad pass, take a sloppy touch, or dribble down a blind alley. Last season saw scant reward for his risks. This season, however, with the exception of his cameo against Spurs, more of what he’s tried has come off in league games.

Alexis being moved into a central starting position has facilitated the upturn in Ox’s game. When the Chilean plays wide, there is an onus on the player on the opposite wing to be more measured in their use of the ball. With two high risk, high reward dribblers in the wide positions, and a midfield runner instructed to get forward to support attacks and show for the ball, last season’s Arsenal would run the risk of over-committing and getting hit on the counter.

Against West Ham and Bournemouth, Arsenal used a noticeably flatter midfield structure than they did between the Watford and Spurs games. Granit Xhaka and Francis Coquelin played more or less on the same lateral line, rather than with the more technical of the pair significantly deeper than the high energy player. Rather than trying to break the opposition’s lines with movement off the ball, Wenger instead opted to use Xhaka’s range of passing. Having two bodies ahead of the back four facilitated a safer version of free form jazz football from the front four.

This sturdy platform and constant supply line from Arsenal’s granite foundations freed the front four to take more risks and play their natural games. It was Xhaka’s range of passing, which is more expansive and adventurous than Coquelin’s and Mohamed Elneny’s, that was the main reason why Arsenal’s front four at The London Stadium weren’t cut adrift from the rest of the team as they had frustratingly been at Old Trafford. Arsenal were able to play out comfortably, quickly get the ball forward, and threaten West Ham repeatedly on the counter.

On another day, with better executed passes against a retreating Hammers side, Arsenal could have had 4 or 5 before half time.

As well as looking dangerous on the counter attack, Arsenal were also able to threaten from open play. One of the key features of this were the supporting runs of Nacho Monreal, both outside and inside the Ox, and working well in combination with him as well as the drifting Alexis and Özil, who popped up to create situational overloads and help Arsenal outnumber West Ham in that part of the pitch.

It was an accomplished performance from Arsenal’s best left back, who looked far more comfortable in the new system and back to his best in defence and in attack, both with and without the ball. Given the absence of Hector Bellerin and less focus on central runners, it was encouraging to see Arsenal’s left flank step up.

Monreal has been much maligned this season.

Some wondered if this was merely because time was catching up with the 30-year-old. This failed to factor in certain other variables. Arsenal’s previous system called for Iwobi to drift infield from the left to pick up the ball in pockets of space. If Arsenal lost the ball, opposition sides would have the opportunity to overload Monreal in the same way that Arsenal’s own left flank overloaded West Ham on Saturday. Against West Ham, Arsenal’s left-sided player would look to stay wider. This would better enable them to get back into a position whereby they could affect play and prevent West Ham creating their own overloads against Monreal. Both Ox, and later Walcott after the two switched sides, were attentive in defence.

Wenger’s tactical tweaks paid dividends against Bournemouth and a poor West Ham.

It will be interesting to see how the formation fares against Stoke and Everton, who themselves will look to crowd the centre of the pitch and then hit their opponents on the counter.

After these matches, the manager will have some big decisions to make over how to approach an away trip to a Manchester City side deprived of the suspended Sergio Aguerö and Fernandinho.

It’s good to know that Wenger has found another way of winning, but he needs to pick the right plan and the right players to execute it in the biggest away trip of the season.