When the big no-nonsense "northerner" - he is actually from Dudley in the Midlands - was unveiled as Hammers boss in 2011 the club was on its knees.
Co-owners David Sullivan and David Gold had been quick to replace Gianfranco Zola the year before with former Chelsea and Portsmouth manager Avram Grant.
The appointment, and lack of any real investment until January, proved disastrous. The owners had also made a rod for their own backs with their rather public pursuit of Martin O'Neill to replace the Israeli, only for the current Republic of Ireland manager to change his mind at the last minute.
For many fans Allardyce was the bitter medicine the club had been crying out for. But some fans were quick to get on the former Newcastle United boss' back during his first sticky spell. Chanting "We're West Ham United we play on the floor" at their new manager was the first hint of any unrest during an away match at Peterborough United.
A day out at Wembley and a 2-1 victory saw the season end in promotion, albeit through the play-offs when West Ham were favourites to go up automatically. Target achieved. Everyone was happy.
Big Sam then became the "safe pair of hands" to help keep the Hammers in the Premier League long-term and reach the Olympic Stadium in good shape come the 2016-17 season. First season back West Ham finished 10th, were never in any danger of relegation and again it was mission accomplished, everyone was happy.
Season three, though, was when things unraveled for Allardyce at West Ham. The ex-Bolton Wanderers boss had hedged all his bets on the injury-prone Andy Carroll and instead of using his remaining transfer kitty on another striker, he plumped to sign Stewart Downing from Liverpool.
There is no arguing that Downing has been a great signing for West Ham and a snip at £6million, but his first season was beset by injuries and a lack of goals and when Carroll was ruled out for much of the campaign, there was a "told you so" attitude from the terraces.
Three wins over fierce rivals Tottenham Hotspur didn't do the 60-year-old any harm but without a focal point to the team - the Hammers played with no striker in several games - they struggled and found themselves in a relegation battle for much of the season. Allardyce blamed an injury crisis for cup humiliations against Nottingham Forest and Manchester City.
It didn't help that his trusted captain Kevin Nolan had gone from hero to villain after ill-discipline saw him sent off twice in crucial games. Nolan eventually got the goals which made West Ham safe during a run of four straight wins.
But the fans were livid with the dour, defensive football they endured for much of the season and made their feelings known. In truth, despite brighter days since, Allardyce has never really recovered.
The owners held a much-publicised summit with him last summer and told him in no uncertain terms they expected better football, more entertainment and a push for Europe.
Allardyce said if that's what they wanted, he needed better players and more of them. And he got it with nine new faces, most of whom have enjoyed fine debut seasons for the club.
But even after leading the East Londoners to their best ever start to a Premier League season, the doubts soon returned when he elected to make wholesale changes to a winning team for an away match at bitter London rivals Chelsea.
Allardyce would argue the side he put out was capable of getting a result. In the eyes of the supporters he had simply handed the club they love to hate an easy three points and in one fell swoop destroyed any momentum built up by their superb run.
The club has won just twice in the league since and although a section of fans maintain Allardyce deserves to continue at the helm, others want to start aiming higher.
Along the way Allardyce has not helped himself at times with his refusal to pander to the romantic notions of some Hammers and their ideals on how the game should be played.
Big Sam seemed to concede very early on that he was never going to be accepted by everyone. So if, as expected, he leaves in May it may be the best for both parties.
One thing is for sure Allardyce, who has never been relegated from the top tier, will not be short of offers of alternative employment.
Rafa Benitez, Marcelo Biesla, David Moyes, Slaven Bilic and Garry Monk have all been linked with the Upton Park hotseat. But should the growing number of fans calling for change get their wish who would, or perhaps more importantly could, take the club on to the next level?