Quick, when was the last game City won convincingly in the Premier League? Some might say the match home to Southampton, but I'd argue you'd have to go back to the match against Bournemouth to find a truly dominant display, and that was back in October. The stats for the most recent six games tell a sad tale:
As you can see, our offensive and defensive efficiency (which measure shots on target per 1000 minutes of possession and opponents' shots on target per 1000 minutes of opponents' possession respectively) have worsened dramatically. The Finish Rate (percentage of shots on target that are goals) has also declined, likely due to Aguero being out for most of the period. Our shots on target difference during this run is just 13th in the Premier League and that's despite facing the easiest schedule (per opponent points per game) over that timeframe.We really need some better performances, which our season totals show is possible, and it needs to start against Arsenal.
One notable aspect of this City season so far is a lack of wins against the better sides in the league. The win over Chelsea to start the year felt big based on the clubs respective positions in the previous season, but Chelsea's utter collapse has put that in a different context. City have failed to win against any of the current Top 5 this year (with Leicester also still to play), and have only beaten Watford, Crystal Palace, and Everton of teams in the top half. Even in the Champions League, City lost twice to Juventus, the best opponent in the group, despite eventually winning the group. A good performance against Arsenal would be a welcome reversal of this trend, and confirm that City actually do deserve to be title favorites.
Are there any reasons for this downturn in form? Obviously, injuries have played a part. Silva, Aguero, and Kompany are the spine of the team and missing them hurts quite a bit. There are also the knock-on affects of the rest of the squad playing heavy minutes, which both De Bruyne and Sagna have admitted was an issue in the press. But there's also been an obvious tactical problem against counter-attacking sides that don't play with a central striker. Against both Stoke and Liverpool (and to a lesser extent Swansea), City were overrun in midfield with attackers moving into positions between the back four and the fairly toothless duo of Toure and Fernandinho, and then runners going behind the static back line. This is something that Arsenal will most likely try and replicate, with Theo Walcott as the false nine making runs beyond the back line and Ozil and Sanchez playing as attacking mids behind him. The fact that this tactical weakness is something that Arsenal can really exploit is another worrying factor. If City can correct it (by playing Delph alongside Fernandinho and moving Toure forward perhaps) and go on to beat one of the best teams in the league, that would really serve notice that there is no one way to beat City.
In short, a convincing win against Arsenal is important for three reasons beyond simple league position. It would stop the run of poor form in the Premier League, prove that City can beat teams of a high caliber, and show that they don't have any obvious weaknesses. I still believe this squad is the best in the league, but it's high time they show it once again. Beating Arsenal would be a great way to start.