The Clarets are seventh on the table with 12 points from their opening eight games, the same amount they had accumulated by Boxing Day last year.
Tarkowski said: "It was one of the toughest days I've had at Burnley in terms of performances and the way the result went against us.
"Since then we've performed quite consistently and picked up some very good points. The difference in performance from that day to today is massive.
"Fair play to the lads because that was a difficult period for us and to come out of that and turn it around like we have has been really good.
"It all stemmed from a good pre-season. Everybody came back in great shape and the competition throughout the squad is brilliant.
"You can see that with the lads coming into the team who haven't started the season; I thought Chaz [Charlie Taylor] was brilliant when he came on.
"To come on after 50 minutes and play the way he did, fair play to him. He worked hard and it can be tough at times being out of the team and then coming in. As a whole squad we're really trying to push each other and move forward. The league table shows how well we've done so far."