Yes I agree with you, even if Arsenal wins this match, it will not have a significant effect on the points difference between Arsenal and Liverpool. Because currently the points difference between Arsenal and Liverpool is very far, which is 15 points. So just winning 1 match will not make the points difference between Arsenal and Liverpool close. But even so, it would be great if Arsenal won this match. Because if Arsenal loses this match, their position will definitely be very threatened. Because currently Arsenal is in 2nd place with 55 points, and while Nottingham is in 3rd place with 54 points, so with this, of course Arsenal's position will be very threatened if they lose or draw with Chelsea. Therefore, Arsenal must be able to bring home 3 points in this match.
Arsenal need to win today's game if they want to retain there second position in the season, there is no roam for them to lose or draw today's game with Chelsea. Arsenal lost the opportunity of moving to number one position when they lost the game against West Ham United followed by two draws. Now there is only 1 point gap between Nottingham and Arsenal. Nottingham finished 17th on points table last season and now competing to finish second this season, remarkable improvement in the performance.
Meanwhile Chelsea has won it's last two games and is in good momentum to win today's game also. Arsenal need to be careful in today's game otherwise they will surly lose second position.
At this point, i'm not even sure of what Arsenal is aiming to achieve this season. Is it to win the title, or to secure the second position, or to just make the top four regardless of where they find themselves. They lost and drew some games that they ought to have won this season. 15 points is not a joke, though they have the opportunity to chop it down to 12 points if only they can win today's game. A sad truth that most people won't admit about this arsenal side is that they keep getting worse every season. Like i said sometime ago, if the Arsenal of last were to play in this season, trust me, they will lift the title with ease. Same thing goes for the Arsenal of two seasons ago.
Mathematically, they still stand a chance though, but not sure if they have that mentality to fight till the very end, and i don't see Liverpool dropping points either. Maybe their outcome in their coming UCL game should be a decider for the season, if to start making preparations for the coming season, or to continue fighting. I can confirm that their new sporting director is now available. Maybe factory resetting the team might help them in the coming season. it's less than 2hrs to the game, so goodluck to both sides. London derby is always interesting to watch.