Sam Allardyce has criticised his Sunderland players following their second-half collapse against Everton.

The Black Cats had pulled the game back to 2-2 at one stage in the second half, before conceding four more goals in the space of 21 minutes.

Allardyce believes that it was an opportunity missed for his side on the back of last weekend's derby-day win over Newcastle United, which he puts down to a "lack of understanding" throughout the squad.

"We've thrown away an opportunity to feel good this weekend," he told the club's official website. "We went behind when we really shouldn't have done, clawed our way to 2-2 and then, for me, that's when we should have been at least coming off with a point today. If Everton had scored a wonder goal you can say 'there's not a lot we can do about that'.

"But the last four goals were all stoppable by us and there was nothing brilliant about Everton's play. That's a lack of understanding of where you're playing who you're playing against. You've got to keep emotional control and you play at this level via the intelligence you've got - ability is all well and good but if you don't have the intelligence with it at this level you lose control.

"All the lads are looking around saying 'what's happened?' They've let it happen, not because of Everton's play but because they've lost their discipline out of possession, and that's a great shame because like I said at 2-2 it was looking comfortable for us and we should of just protected that."

Defeat for Sunderland leaves them two points adrift of safety in 19th place, with games against Southampton, Crystal Palace and Stoke City to come before November is out.