West Ham United manager Slaven Bilic was bitterly disappointing after his side threw away a 2-0 lead against Watford on Saturday afternoon.
The Hammers suffered their third English Premier League defeat of the season as they sit in 17th place in the table.
And they will be looking for an improvement when they face West Bromwich Albion away from home next week.
"It's hard to explain," Bilic said.
"Their first two goals were way too easy. OK, the second one was a classic for YouTube with no communication between two players, but that happens. Of course it shouldn't but it happens.
"Their third goal came from a very predictable attack and we should have made it more difficult for them to hurt us.
"It had already happened twice in the first ten minutes, when we had five chances and they had two, and it was too easy for them to get in positions out wide in space.
"Then, when they have the ball, you shouldn't allow a two-against-one situation to develop and allow your player to be exposed and hurt, because then they can use their quality."