They are a point ahead of Manchester United, although their rivals can reclaim top spot with victory over Sheffield United on Wednesday.
“A few home truths needed to be said, it had to be done now because there’s a short period of time before the next game,” said Allardyce, who held a dressing-room inquest for almost an hour after the game.
“These next two games (Fulham and Sheffield United) really stand high in what we need to do. I needed to get my feelings to the players out of the way. They needed to air their views, which is fine as we are all in it together.
“I was disappointed in the performance and to get it out the way means we can learn from it and we don’t see it again. I can accept defeat but not like that.
“What will determine our fate comes in the next two games. A win and a draw is the least we have to try to get.
“We have got to work out what it is, playing at home. There’s no pressure from the fans so we have to work out what.”