Everyone knows that there is an invariable tendency for ex-players to score when playing against their former club.
Chelsea have two ex-Arsenal players: Cuntly and Anelka.
We have Gallas.
Does that mean the match will finish 2-1?
No, of course not. It's a London derby and anything can happen. But, there will be extra spice for those players. And Cashley has never played well against us since he left.
Fundamentally, it's about how different players react to negativity. Whenever Arsenal play Chelsea, Cashley gets booed and it seems to affect him. On the other hand, Gallas scored the winning goal last year at the Grove. When we lost the Champions League final in 2006, Thierry followed that up by signing a new contract and in no uncertain terms, showing his disdain for Marquez and Puyol. But clearly, whilst defending is always important, it will particularly be the case in this match.
And so Gallas will be vitally important. This game won't finish 3-2. Or at least I'd be very surprised. I can't see there being more than 3 goals in the game, because this will be a tight, tetchy match. But Chelski are missing Carvalho, their best defender, and Essien, their best midfielder. So whilst on paper Chelsea might be favourites, this turns it back towards Arsenal.
However, looking at the game in an overall sense, what is clear, is that Chelsea will probably create less than United did 3 weeks ago, but they will be more clinical. So, we have to stop their creative players. And our full-backs have to stop their's getting forward.
People will say that beating Man United and Chelsea means nothing if we don't win the league. Or, that all it gives us is a chance to brag in school or at work. They are wrong!
If we fail to win the league because of our results against the big 4, the best players will say the starting eleven isn't good enough and leave. But, if we don't win the league, then what will persuade our best players to persevere with this football club, is the knowledge that if we can beat the best teams, all we need is a little bit of steel. So it matters enormously, not just in giving us some momentum in the league, but also, in terms of the future of the club.
Vamos William, vamos Arsenal - you can do it...