As Best and his fellow Ulster team mates head south for Saturday night's clash with the RaboDirect PRO12 leaders they will no doubt be asking themselves how they have managed to blow an 11 point lead at the top and now find themselves one of the top in third place with four games left to play.
"It's been frustrating for everyone over the last five or six games. When you look back at it, except for the Edinburgh game, we have actually played well in parts," said best, who hasn't played for Ulster since the final Heineken Cup Pool match against Castres Olympique..
"We probably played some of the best rugby of the season in the home game against Treviso, but we didn't get reward for that. We had a lot of pressure and didn't put on points and when you are missing experienced players they are the little things that you only learn with time.
"Saturday night is going to be a tough ask because Leinster have won nine in a row, but we're looking forward to it and it's one we are confident we can win."
While Best returns to the Ulster starting line-up after RBS 6 Nations duty along with Craig Gilroy, head coach Mark Anscombe has made a number of other changes to the team beaten in Edinburgh last weekend.
Ruan Pienaar and Chris Henry return to the side having recovered from injury, No 8 Nick Williams his first game since suffering a knee injury in January and Ricky Lutton deputises for John Afoa at tight head prop while the ex-All Black is home in New Zealand for the birth of his third child..
Robbie Diack, who started at No 8 against Edinburgh, switches to blindside flanker for the game, while Dan Tuohy reverts to his usual position in the second-row. Rob Herring, Lewis Stevenson and Paul Marshall drop to the bench where they are joined by back-row forwards Roger Wilson and Iain Henderson, who have both recovered from injury.