In a sign that Aidy Boothroyd's changes are not going unnoticed, Fletcher said: "We knew it was going to be tough here.
"There won't be many teams come here and keep a clean sheet and we did very well to keep one."
Teams basing their strategy on how to deal with the Cobblers' threat provides a new challenge for Boothroyd but it is a very welcome one as his side look to confirm their safety and lay foundations for a much better season in 2012/13.