The Gunners, who sit level on points with leaders Manchester City, go into Saturday's match at West Brom after winning eight and losing two of their opening 12 Premier League games this season.
Wenger will demand his injury-plagued team, who are 12 points ahead of the Baggies, are at their b est at The Hawthorns to earn another victory
"You don't even look at the table anymore because you know what you get," Wenger said.
"The difference between the teams has narrowed and that today it's more how close you can be to your best that will decide the result than the team you play against."
Wenger has been impressed by the Baggies, who have lost four of their last six Premier League games, including 2-0 at Manchester United prior to the international break.
"I watched them against Man United and they looked a very well organised team who is absolutely, as always with Tony Pulis, totally committed," Wenger added.
"On top of that they are in a difficult situation, a little bit, in the Premier League.
"You expect what you get now in the Premier League from everywhere: a committed, physical, fast game and a game where we cannot afford to make any mistake."
Wenger will assess Laurent Koscielny and Olivier Giroud's readiness to play after the pair's involvement for France during the international break, when terrorists struck in coordinated attacks in Paris.
Wenger says defender Koscielny, in particular, appeared affected in Tuesday's match with England at Wembley.
Right-back Hector Bellerin is available following a groin problem, but midfielders Alex Oxlade-Chamberlain and Aaron Ramsey (both hamstring) remain out this weekend and forward Theo Walcott (calf) is not expected back for "one or two weeks".
Source : PA
Source: PA