The Gunners would be second in the Premier League, two points behind Manchester City, if just second-half scores were taken into account.
Wenger, whose side clawed their way back from two goals down against Liverpool on Wednesday, said that Arsenal's failure to perform in the first half could be a psychological issue.
"Maybe the psychological factor, the fear not to do well, lies in our first halves," Wenger told reporters. "But when we are in a position where we really have to go for it we show extreme quality.
"I think we did that again against Liverpool on Wednesday. We can be very proud of our performance in that game because the players had huge mental strength and great quality in our game."
The French coach was full of praise for today's opponents Stoke City, who he believes have added more technically gifted players to their squad.
"Stoke are a team that are usually well-organised and difficult to beat," he added. "You expect always a fierce resistance from Stoke and most of the time you are never disappointed.
"They have gone for more technical quality these days, they have brought Charlie Adam and Steven Nzonzi who are technically good players in midfield.
"That means they have more variety in their game and they have shown that many times this season. And, of course, you know they can compete with anybody."
Arsenal and Stoke drew 0-0 at the Britannia Stadium in August.