Saturday's 0-0 draw with Brighton left the Reds level on points with Gus Poyet's side and three shy of the top six.
"We are doing our best for it (promotion)," the former Chelsea striker Hasselbaink said.
"It depends on a lot of factors, you need a little bit of luck and you need everything to go for you.
"We had a really good result against Brighton. Brighton played quite well in the first half and should have scored one, but we had some chances as well and hit the bar.
"In the second half we were really good and could have won it. But we drew 0-0 and that was a good result. We are on the right track."
He added: "It is a very tight division. Everybody can beat everybody - look at Cardiff who were beaten by Peterborough at home.
"Peterborough, bottom of the league, beat the top of the league. That is what you are working with. It is the hardest league to get out of."