Here are five reasons why it happened ...

1. The dedication to a 3-4-3 formation was shown up by performances and results

De Boer made it clear that he saw Palace playing in a 3-4-3 formation. He played with it throughout preseason, and then in the club's first three competitive matches. Despite the work before the season kicked off, Palace barely looked comfortable.

The 3-0 defeat to Huddersfield would have been seen as an acceptable part of the learning curve had the manager shown a willingness to adapt. But Palace persisted with the tactic, albeit in a more defensive stance against Liverpool. De Boer's side limited Jurgen Klopp's side to just one goal, but the porous way the squad played, in midfield especially, was still alarming.

The Swansea game should have been a point of clear change. It wasn't, and by this point it seemed the Palace owners had grown distrustful of the manager they took six weeks to recruit. The Burnley defeat could, in theory, have given the manager more time. But by that point it seemed that Steve Parish, David Blitzer and Josh Harris had made up their minds.

2. It wasn't just a matter of tactics

The most alarming elements of Palace's run of defeats weren't just the results but the lack of urgency, or intent, in the squad during de Boer's reign.

The game that seemed to turn the chairman's opinion on the manager was the Swansea defeat. Palace allowed the visitors to dominate possession for much of the first half, and handed them two goals either side of half-time. The passing wasn't crisp and there was an unwillingness to win the ball back. It took the half time team talk and a change in formation to give the side some incentive but that lackadaisical approach to passing and movement still continued.

The same happened against Burnley. While Palace created numerous chances, the weakly hit passes and lack of movement, especially when in possession, was still troubling. That Palace couldn't finish any of the 22 chances they created would have been the final nail in De Boer's managerial coffin.

That's not a tactical issue but one of application.

3. If you're trying to evolve, fitting square pegs in round holes doesn't work

Palace's tactical listlessness was further worsened by de Boer's attempt to adapt specialist players into roles that didn't suit them. The first clear sign of this was his decision to play Andros Townsend at right wing-back in preseason, only to then decide before the game against Huddersfield to play Joel Ward in the position. This in itself was a questionable tactic because the manager hadn't played Ward at right-back all preseason, preferring instead to utilise him as a back-up centre-back.

That was just a taster to the disjointed approach to tactics, though. Lining up Luka Milivojevic, a specialist defensive midfielder, at centre-back was another clear issue. It seemed at the time to be a gesture to his chairman that he needed another centre-back.

De Boer could have cut his cloth accordingly, but he didn't. It ultimately cost him.

4. When a manager falls out with an owner, there's only going to be one winner

Whatever the cause of the fallout between the manager and the chairman, when a relationship between two key stakeholders at a football club breaks down with no sign of it being repaired, something will inevitably change.

That relationship issue came to the surface following the Swansea defeat, and while there was some hope that matters might change, the briefing that seemed to be fed to the media suggested that there was a deep-lying problem that couldn't be resolved.

De Boer's sacking wasn't just the result of defeats but of what seem to be a number of factors -- the disagreement with the chairman was clearly at the heart of it.

The timing is embarrassing for the club, but if there's a genuine belief that the professional relationship can't be repaired, the decision to sack him had to be made sooner rather than later.

5. The new manager must work with his team's strengths

Whoever comes in to replace de Boer, he will have to make use of a squad that lacks balance but is clearly capable of collecting better results than it has done already.

Palace have enough players who can make their opponents work hard -- a defence of quality players, a midfield of internationals and a striker who is arguably one of the best headers of the ball.

While under de Boer, Palace's style left Christian Benteke feeding on scraps rather than crosses. And on the basis of preseason and the opening game against Huddersfield, Wilfried Zaha is isolated when he should be the player whom everything went through.

The new manager will be tasked with making these players tick. A squad of individuals needs to be a team of quality. That's where de Boer struggled. It's where his successor needs to excel.