Chelsea manager Andre Villas-Boas insists referees should pay for errors over 'diving' players in the Premier League Referees have pretty clear orders on simulation. But it is difficult for them to assess the difference between simulation and fouls in those situations," said Villas-Boas, whose side travel to Everton on Saturday. They need the right backing to decide on these actions, and when it's simulation a yellow card should be given. The game is faster than when I last worked here a few years ago, and that impacts on decision-making by the referees, who are professionals, but I'm sure they are adapting. And as years go by hopefully you will see better performances from the ref. Now it is up to Mike Riley and the governing bodies to decide if the refereeing is up to the right level and to punish the ref. My view on our last game is that, if a referee is going to award two penalties away from home to the same team, he should be 100 per cent sure they are both penalties. Howard Webb was obviously 100 per cent sure in his own mind - my opinion is different, that he was wrong, end of story. In the end it is the player who proves his smartness - some are called cheats and divers, others are clever and smart for making the most of the situation, depending on your perspective. But the second one last week triggered United's comeback: at 3-2 they were right back in the game.