Even a draw may not be enough to keep Hoffenheim's survival hopes alive going into the final weekend of the season, with two points to make up on either Augsburg or Fortuna Dusseldorf above them.
But Gisdol is focused only on getting a win on Saturday.
"Calculating all the permutations gives you a 0.0% better chance of winning," he said. "We are doing all we can to be successful, which is why we're not making any calculations."
Hoffenheim's recent performances have started to lure the fans back to their Rhein-Neckar Arena, which will be sold out for Saturday's match.
Gisdol hopes those fans will see enough to want to come back again next season, preferably still in the top flight.
"We have spread a lot of joy around here lately with the way we try to play football," he said.
"We have sent out clear signals in recent weeks as to where we want to go and how we want to win the fans over.
"There is life in our game again."
There is still life in Hamburg's season, according to their coach Thorsten Fink, who is not giving up on their chances of qualifying for Europe next season.
The northern Germany side need to make up three points on sixth-place Freiburg to sneak into the Europa League and Fink is not throwing in the towel just yet.
"It is still mathematically possible," he said. "And we want to ensure that is the case right to the end and we will give everything for a place in Europe."