But just three wins since have seen them slip to 11th place with their latest defeat coming in the last minute of stoppage time against Everton on Saturday.
The steep decline in the Hammers' form has led to intense speculation over Allardyce's future at the club.
Allardyce had made peace with the arrangement, conceding that is how it has been since he arrived at the club four years ago.
But when results dried up it did not take long for the relationship between owners and manager to become fractious.
Sullivan recently admitted he was disappointed with how the season had panned out while Allardyce maintains he has done everything asked of him during his tenure.
All and sundry have been linked with the Upton Park hotseat as potential replacements for Allardyce.
And ahead of the Everton match, there were the first murmurings of discontent from Big Sam who admitted in his London Evening Standard column that he worries there is 'no smoke without fire'.
There were calls for the manager's head last summer off the back of a disappointing 13th-placed finish and brief struggle against relegation.
Some fans were fed up with the style of football and what they saw as Allardyce's negative approach, particularly to away games.
Sullivan and Gold kept Allardyce at the helm but issued him with an ultimatum to play more entertaining football. Teddy Sheringham was appointed as an attacking coach and a raft of summer signings were brought in to supplement the new approach.
But now, with the fantastic first half of the campaign a distant memory, Allardyce has blamed the demand for more expansive football and a lack of squad depth for the club's inability to close out matches, like yesterday's defeat to the Toffees where the Hammers had been leading 1-0.
Speaking to the club's official website, Allardyce said: "The overall assessment is about this. Absolutely brilliant and then the squad not being quite good enough to stay in and around eighth position in the Premier League.
"Injuries have made a big difference because the goals dried up. And because we are more open and more attacking, which is what everybody wanted, we've not kept as many clean sheets as last year which was 14, we're in single figures this year.
"Had we got a clean sheet we'd have won 1-0 and everybody would be happy. Had we kept a clean sheet against Manchester United we'd have won 1-0 and we'd be happy, had we kept a clean sheet here against Stoke 1-0 everybody would be happy. Had we got a clean sheet at Tottenham we'd have won 2-0 everybody would be happy.
"We've got to balance that up and get everybody learning next season just how difficult it can be."
Whether the former Newcastle United and Blackburn Rovers boss is around next season remains to be seen. Yesterday's last gasp defeat could be Allardyce's final game at the Boleyn.
Rafa Benitez and Slaven Bilic are said to be top of the club's wish list to replace Big Sam, who insisted earlier this week that he is the man to lead the Hammers into Europe if, as is expected, they qualify through the FIFA Fair Play table.