Watford manager Tom Cleverley felt his side deserved a point from their 2-1 defeat by Sheffield United, but admitted they lacked a killer instinct.
Gustavo Hamer and Andre Brooks netted either side of Jeremy Ngakia's strike to secure victory for the Blades.
Watford have now won just two of their past six games, losing four, which has seen them slip four points adrift of the play-offs.
"One team knew how to win, the other is pretty new to it. There is not much between the teams," Cleverley told BBC Three Counties Radio.
"I told the players the month of December finds teams out and it has found us out.