There are times when the cheap option ends up being the most costly one. Although it is easy to understand why West Ham decided not to sack Slaven Bilic at the end of last season and instead chose to let his contract wind down before finding a replacement next summer, the harsh truth is that they should have acted by the time official confirmation arrived on Monday morning. The evidence had piled up long before Saturday’s humiliation against Liverpool. West Ham tried to ignore it but the consequence of waiting is that they find themselves now hoping that the man who took Sunderland into the Championship will offer them salvation.

David Moyes was ready and waiting when the call from David Sullivan came before the 4-1 defeat by Liverpool and that made the former Everton, Manchester United and Real Sociedad manager an obvious pick to replace Bilic. Candidates who might have taken the job in the summer have become unattainable and West Ham did not fancy the prospect of engaging in the laborious and expensive process of prising a manager away from a rival club. Unlike Burnley’s Sean Dyche, there are no complications with Moyes – other, that is, than his dire record since leaving Everton in 2013, which is why many supporters view him as an uninspired choice.

From West Ham’s perspective, hiring an experienced disciplinarian is sensible. They did not succumb to the Premier League’s culture of reactive impatience but were patient with Bilic and sacked him, with a heavy heart, only after accepting that the decline under him was irreversible. Sullivan and David Gold, the co-owners, remembered that relegation was the punishment when they inexplicably allowed Avram Grant virtually a full season in 2010-11. This time they have made their move after a start that has left West Ham in 18th place with the worst defensive record in the Premier League.

Timeline Slaven Bilic at West Ham Show Named West Ham manager Bilic joins on a three-year deal from Besiktas, replacing Sam Allardyce. "It is a big privilege and a big responsibility," he says. "We want to make a big club even bigger." Away wins fuel flying start Victory at Manchester City follows away wins over Arsenal and Liverpool – the club's first win at Anfield since 1963 – moves West Ham second in the Premier League table. Goodbye to the Boleyn Ground West Ham finish the season in seventh and secure a Europa League place, but Bilic sounds a cautionary note as the club leave the Boleyn Ground. "It is impossible to make the Olympic Stadium a fortress like this. Forget about it – no chance." Moving troubles Sure enough, it’s a nightmare start at the new ground: disorder in the stands and a 3-0 defeat to Southampton their fifth loss in the first six games. They’re also beaten in the Europa League play-off. Vote of confidence Co-owner David Sullivan issues a vote of confidence after a 5-1 home hammering by Arsenal. "Slaven cares passionately about the football club and this defeat will be hurting him as much as anyone." Payet says goodbye Dimitri Payet returns to Marseille after refusing to play in order to force a move. “This team, the staff – we gave him everything, we were always there for him," says Bilic. "I feel let down. I feel angry.” More backing from the board West Ham climb into the top half before a run of five straight defeats results in another vote of confidence. "To end speculation once and for all, the board feel it necessary to announce that we have 100% faith in Slaven Bilic’s ability to lead West Ham United." Season ends with a whimper A 1-0 win over Spurs at home provides a lift – but they lose the next one 4-0 to Liverpool. “I wanted the same performance as against Spurs. We didn’t do it. We wanted to avoid complacency but it was obviously there." Closer to the edge Bilic is on the brink after West Ham lose their first three games – but hope is restored with a battling 2-0 win over Huddersfield. "The lads did everything we asked. We acted well at a difficult time." Cup win lifts spirits West Ham lose 3-0 at home to Brighton to leave Bilic facing the sack – before a rousing away win over Spurs in the Carabao Cup. “The lads deserve it, it’s a great night for the club. This should be the standard from this point on.” Liverpool loss proves final straw West Ham throw away a 2-0 lead in a draw at bottom club Crystal Palace, before a 4-1 defeat at home to Liverpool. Bilic is sacked two days later, with David Moyes expected to take over.

The other way of looking at it, though, is that West Ham let a torrid situation drag on while their rivals improved. Bilic was immensely popular at West Ham. His bosses liked him – “a delight to work with,” according to one senior figure – and were impressed with his candour when they interviewed him after Sam Allardyce’s departure in 2015, even though Rafa Benítez was their first choice before he joined Real Madrid. Yet Bilic’s team have been awful for 15 months. The defeat by Liverpool was the 10th time they have conceded at least three goals in a home game since moving to the unloved London Stadium.

The Croat’s first season was deceptive. Yes, West Ham enjoyed victories over Arsenal, Chelsea, Liverpool, Manchester City and Tottenham Hotspur and finished seventh. But Dimitri Payet was inspired, Bilic inherited Allardyce’s solid defence and there was the buzz of the Upton Park farewell. There were times when West Ham rode their luck. They fought back from losing positions a lot, which was unsustainable, blew Champions League qualification by conceding 20 goals in their final 10 games and there was unease when Bilic tried to turn Michail Antonio into a right-back.

The rot set in as West Ham struggled to adapt to the London Stadium last year. Intensity in training dipped, Payet returned to Marseille and speculation over Bilic’s future mounted. Scrappy wins kept saving him but the football was lethargic and disorganised. Opponents loved playing against West Ham, who sounded out David Wagner at Huddersfield Town and Hull City’s Marco Silva in March. Bilic was convinced the end was coming. One of his assistants, Edin Terzic, mulled over taking a job in Germany. Yet West Ham, who finished 11th, decided to stick with Bilic after the raucous home win over Tottenham in May.

That result papered over the cracks. After spending £40m on Marko Arnautovic and Javier Hernández, signing Pablo Zabaleta on a free and bringing in Joe Hart on loan in the summer, West Ham lost their opening three league games and Bilic’s relationship with Sullivan, who doubles as the club’s director of football, became increasingly strained after the failure to meet Sporting Lisbon’s £37.5m asking price for William Carvalho.

Bilic limped on, scraping wins over Huddersfield and Swansea, but his football lacked identity and style and he was too reliant on Manuel Lanzini’s invention. There was too much focus on motivation and not enough on tactics. A player who left in the summer was perplexed by Bilic’s speeches about playing with passion. Where, he wondered, was the level of detail he had experienced at his former club? Another defensive player was baffled by the way he was left exposed by the team’s shape out of possession. Defenders regressed and there is a belief within the squad that they are unfit. There have been too many soft tissue injuries and Bilic was damned by statistics showing that West Ham have covered the least distance and made the fewest sprints in the Premier League this season. It was no surprise when they contrived to concede from their own corner against Liverpool.

There was not enough accountability. Allardyce would make sure mistakes would not be repeated by hammering the culprit in front of the rest of the dressing room but Bilic was afraid of confrontation. That timidity conspired against him when West Ham unprofessionally threw away a 2-0 lead against Crystal Palace, setting in motion the chain of events leading to Moyes. Relegation is unthinkable in the London Stadium.

Bilic had to go and the irony of his replacement is that it is three years since Allardyce was talking about how West Ham needed to emulate the reliability of Moyes’s Everton. But delaying an awkward decision means that Moyes, who will need to strengthen a talented but unbalanced squad in January, is set to arrive on an initial six-month contract, a short-term fix for a club in urgent need of clearer direction.