Arsene Wenger probably didn't sleep well on Saturday night. Tossing and turning with the injustice of the day’s events at Stamford Bridge still feeling very raw indeed. And who could blame him. On an afternoon where the form book suggested he might finally defeat Mourinho in a competitive game, a positive start was undone with an early red card for defender Gabriel seconds before half time. Predictably, Diego Costa was at the centre of it all. It was a nasty, provocative performance from the Spain international, fully justifying his reputation as the Premier League’s go-to pantomime villain. 

In case you didn’t know, Mourinho and Wenger don’t get on. And despite a rather forced handshake before the game, a certain animosity was present on the pitch from the first whistle. Diego Costa and Arsenal’s defenders aside, at its core this was a contest between two managers at opposite ends of the footballing spectrum. Mourinho’s win-at-all-costs pragmatism verses Wenger’s own brand of expansive, aesthetics-first football. There were bound to be fireworks in such a collision of philosophies.

This difference in mentality perhaps explains why Mourinho assembles his title-winning teams with more than a fair share of gritty, streetwise players. Essien, Carvalho and Drogba in his first stint at Stamford Bridge; Lúcio and Diego Milito in his days at Inter Milan; Matic and Diego Costa are vital cogs in Chelsea 2.0. All warriors and all, inevitably, winners. In contrast, the post-invincibles era has seen Wenger spend the majority of his money on nifty, number 10-types, from Arshavin to Cazorla to Ozil to Sanchez, as he seeks to prove that success on the pitch can be achieved the right way, with football in its purest form.

Chelsea v Arsenal - Premier League

Unfortunately for Wenger, as was clear against Chelsea, the margins between triumph and defeat at the highest level are desperately fine. Skill and technique alone often aren’t enough to guarantee a win. Other, less quantifiable qualities make a telling contribution. Drive, determination and steel, not to mention the important ability to take advantage of the game’s dark arts.

For example, would Pep’s, or indeed the current Barcelona side, have been as successful without the antics and gamesmanship of Sergio Busquets in midfield? The man is as fine an actor and manipulator of referees as he is a player – which is saying something. Last season a Celta Vigo player was sent off for throwing grass as Busquets. For throwing grass!

Barcelona v Inter Milan - UEFA Champions League

If you cast your mind back to that famous Champion’s League semi-final between Mourinho’s Inter and Barcelona in 2010, you’ll remember that Busquets was responsible for Thiago Motta’s sending off. It forced the Italians to hold on for over an hour against one of the best club sides of all time. It was a crazy, unforgettable match displaying both the dark arts fluency and the mental attributes currently lacked by Arsenal’s players. Mourinho’s team came through that game exactly because of those intangible qualities: a will to win, steel and determination.

The debate between football's dark arts and those who want a clean game is in many ways irrelevant. As much as we want to turn our noses up at diving, play-acting, deliberate provocation and the like, there’s no doubt that it’s an element of the game there to be exploited. Sadly it will remain so until technology is used to assist referees who simply can’t keep their eyes on all players at all times. 

In a perfect world Arsenal’s free-flowing approach would see them coasting to the title every season. Unfortunately the Premier League is far from perfect. Mourinho will argue that winning ugly is still winning, and in the years to come this will simply go down as another game in which Wenger couldn't get the better of him.

It's likely that true footballing perfection lies somewhere in between the extremes of Wenger and Mourinho. This perhaps explains why a Manchester City squad bursting with grit, presence and flair in equal measure look favourites to win the league this season. 

Believe it or not, Diego Costa didn

It says a lot that had Diego Costa been playing for Arsenal on Saturday, they probably would have left Stamford Bridge with three points. His contribution, however controversial, made all the difference in the end.  

After a summer where Arsenal were the only club in Europe's top leagues not to sign a senior outfield player, Wenger desperately needs to add some steel, and perhaps a touch of nastiness to his team of charming young men. Without these attributes they will continue to lack the ruthlessness required to win league titles.

Chelsea v Arsenal - Premier League