Arsenal boss Arsene Wenger believes there is one thing he needs to find for the club to make the most of their attacking talent - and that's balance.
The Gunners have terrific talent at their disposal, with Alexis Sanchez, Mesut Ozil, Olivier Giroud, Santi Cazorla, Danny Welbeck and Theo Walcott - yet while that consists of six players, only four offensive positions exist in his formation.
His selection decision was made easier against Spurs by Sanchez being ruled out injured, and his choice of players did not click, losing the game 2-1.
He suggests however that he is not the only boss facing a similar dilemma, pointing at Barcelona's failure to get star summer signing Luis Suarez scoring like he did at Liverpool.
He told The Sun ahead of the derby: "The teams at the top have great offensive power. City, Chelsea, Liverpool, United — it’s the same everywhere. But it’s not just about numbers, the real challenge is to find the right balance
“For example, if you told me that Luis Suarez would score only two or three at Barcelona when he scored 31 last year, I’d say it’s impossible. But it’s about players finding their space, room and aura in the team.”
So what went wrong against Spurs?
Per Mertesacker told Arsenal's website he believes the club's inability to launch effective counter attacks played a big part in the North London derby loss.
Arsene Wenger had a big decision to make with Alexis Sanchez out injured, and chose to fill the void with Danny Welbeck, but the England international was unable to make an impact playing out of position out wide.
With Mesut Ozil far from a convincing wide player, Arsenal were too narrow against Spurs, and were unable to stretch them in the second half.
Certainly a player like Luis Suarez, or more specifically Alexis Sanchez, would have made a substantial difference had he not been sidelined by injury.