West Ham United boss Sam Allardyce has urged Andre Villas-Boas not to be too stubborn with his tactics at Chelsea.
Allardyce wrote in the London Evening Standard: "On the pitch, it looks as though Chelsea have stopped defending correctly out of possession, not the back four but the team.
"Playing a high line could be part of the problem because people work it out. That's why Bolton used to beat Arsenal - they'd never drop off so we would encourage our players not to play to feet but to go diagonal in behind and get the wide players to come in off the line. If something isn't working, then you have to change.
"I would say Andre has to change his philosophy at this time, not completely dismantle it and not permanently but just until his team get back to winning ways.
"I watched Carlo Ancelotti come to England, start with the diamond before he realised he couldn't do it here. I watched Jose Mourinho come here and change to a 4-3-3.
"When I began at Blackpool my philosophy worked. I got them from the bottom of the division to the play-offs in two seasons. My next managerial job was at Notts County and I introduced the same practises there.
"It never worked. I went there in the February and they went down.
"Now I knew I had 10 games to save my career the following season and that really concentrated the mind.
"I knew I had to have a deeper look at what used to work, why it wasn't working then and how to change it.
"I decided to play a back three on the basis that the only place you could get caught out with that system was with the opposition full-backs and, in that division, they weren't good enough to damage you. It worked a treat and we walked the League that year.
"With Andre, he has come such a long way in a short space of time. It's similar to when you break through as a young player. You're in the first team, things are going well and then you miss a pass, then another, you make a mess of a header and suddenly it's not as easy as you thought it was going to be.
"It's then you need the help of the manager and the coaches. It's a defining moment. With their help and your determination you can come back and be a top player.
"It's the same being a manager and if Andre comes through this, he will be a fantastic manager.
"In the short term, though, and in my humble opinion and not meaning to be critical, he has to change in order to win football matches again as quick as possible."
