However, with the race for fourth being so tight Hamman says there can be no slip-ups in the coming weeks.
"It's hard to say what's going to happen because everyone seems to be dropping points," he said.
"We've got 30 points to play for but we've also got to go to Highbury and Old Trafford.
"I think we definitely need to get over 20 points to finish in the top four. Maybe 25 points would do it. I think we're looking at six, seven or maybe eight wins before the end of the season.
"But the most important game now is the one against Wolves on Saturday and we shouldn't look too far beyond that.
"It was important to get the three points with our game in hand last night and get closer to fourth. From the word go we pressed Portsmouth hard and made chances and deserved to win."