Mikel Arteta has revealed Arsenal's set-piece prowess was a decade in the making.
Since the start of last season, the Gunners have the best record of any team in Europe from dead-ball situations having scored 23 times.
Their domestic dominance from corners is clearer, having scored 37 times -- 16 goals more than any other Premier League team during the same period.
Ahead of Crystal Palace's visit to Emirates Stadium this weekend, Arsenal are top of the table having extended their perfect record in Europe to three wins from three after hammering Atlético Madrid 4-0 in midweek.
Asked when he realised set-pieces would be such a pivotal part of his approach, Arteta said: "Ten years ago. I wasn't here but 10 years ago, I said 'it is a massive thing to do that' and I started to have a vision, try to implement a method and try to be surrounded by the best people to deliver that."
Arteta was undertaking his coaching badges during the 2015-16 season, his final season as a player at Arsenal, before joining City where he met Nicolas Jover, who would later become set-piece coach at Brentford before joining Arsenal in 2021, less than two years after Arteta became manager.
"I went to City with the best manager in the world and I could see where we could have improvements and it was clear because at some point I was doing that and I wasn't the best person in the world to do that," he said.
"So if I am not the best person in the world to do that and the best method to do it, there are ways to improve it. And you could see that straight afterwards what started to happen.
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"But [I am] not only obsessive about that, I am the same in the defensive part, in transition, I want to be the best when it comes to chaos, I want to be the best when it comes to positional attacks, the best when it comes to low blocks.
"That's the eagerness to constantly find ways to develop your team and give your players to be more unpredictable and especially more efficient."
Gabriel Magalhães is a doubt for the game with a muscular problem which has left him unable to train following Tuesday's win over Atlético.