The Londoners currently lie in seventh place in the Premier League table with new strikers Diafra Sakho and Enner Valencia making an immediate impact - but Sullivan believes it is the switch to a diamond formation that has brought about the upturn in form.

"There is a lot of optimism about the place now," Sullivan told the Evening Standard.

"I genuinely believe we have the best squad since we've been at the club. We've signed some high-energy, younger players and we have discovered the 'West Ham way'.

"He, Allardyce, changed the style after that to a diamond formation. Sam made that decision so he deserves the accolades because, had it not worked, he would have been castigated.

"We have a policy - and it's as much for Sam as us - that we sit down at the end of the season, maybe a bit earlier if we're safe, and judge things over an entire season.

"We've always done it that way. Last year I was being asked at various times if Sam would be going but my answer was always that we'd look at it at the end of the campaign. We're very loyal to our managers

"We always talk on a Monday or the day after a midweek match and if he has a problem he calls me. We all want the same thing and that is the best for this club.

"Sam wants to be successful and he's very flexible at looking at ways to achieve that. The change in formation was not my idea - he's the one who made that bold decision to change the strategy."