Crystal Palace appoint Patrick Vieira: Expected goals and expectations for next season

Roy Hodgson was in charge at Palace for four years

The red warning lights are on. Statistically speaking.

Crystal Palace's underlying performance numbers - chiefly, xG (expected goals) and xGa (expected goals against) - are among the weakest in the Premier League. Even a quick glance at last season's table will tell you Palace had the worst goal difference outside of the relegated clubs. The signs are there to suggest further struggles in 2021-22.

Midway through a summer of change and with a new manager in post, BBC Sport data analyst Andrew Bassett and football reporter Alex Howell discuss where the Eagles are now.

Andrew Bassett: Palace had the second lowest xG total last season, meaning they were poor at generating goalscoring opportunities. However, they did outperform their xG by 6.52, the highest among teams who finished in the bottom half of the table. Wilfried Zaha contributed almost three goals above expectation, with Christian Benteke, Eberechi Eze and Jairo Riedewald also chipping in.

Did those players mask the deficiencies in Roy Hodgson's attacking approach?

Alex Howell: There's no doubt how much of an impact those players had on where Crystal Palace ended up last season. If you take out Benteke and Zaha's contribution, you lose half of the goals they scored in the Premier League. Zaha was often relied upon to travel up the pitch with the ball and make something happen. This allowed the defence to have a breather, but usually meant he had to produce something pretty special to score. He mainly played as a striker so it's not a bad return for someone who was asked to do so much. Benteke had a revival season and got into double figures for the first time since the 2016-17 season.

Christian Benteke scored 10 league goals for Palace in 2020-21

AB: The defensive stats weren't great either. Palace had the third-highest xGa total over the season, behind only Sheffield United and West Brom. This means they were offering goalscoring chances to their opponents more frequently than most teams. Again, Palace outperform the xG model but this time in the negative sense, allowing 6.6 more goals than the xGa prediction.

This data points towards Palace being one of the weakest sides in the league for expected attacking and defensive output. A statistical model built by FiveThirtyEight places Palace as the third-lowest team on their SPI index in last season's Premier League.

As it stands, should we expect a relegation battle next season?

AH: It's no secret that Patrick Vieira has a big job on his hands. Palace have usually been an effective defensive team, but injuries, bad luck and poor performances damaged their solidity. It could also be a factor of age catching up with some players. Scott Dann, Gary Cahill, James Tomkins, Mamadou Sakho and Cheikou Kouyate all played centre-back for the Eagles - but are all the wrong side of 30.

Vieira, the former Arsenal invincible, was sacked by Nice in December, but the 44-year-old had been highly rated before that. He had led the team to seventh and fifth in Ligue 1 in his two and a half years there and had even been mentioned as a future Manchester City manager by a senior member from the City Football Group.

Palace fans will be hoping for attacking football after Hodgson's spell in charge, which was largely focused on the team being hard to beat.

AB: Seven of Palace's 12 league wins last season were against the six teams who finished below them - including five in the six matches against the bottom three. Is this coincidence or did Palace target these games as winnable 'six-pointers'?

AH: Hodgson always stressed the importance of picking up points against the sides around them in the league. Palace are now entering their ninth successive season in the Premier League and along the way have signed some top-level quality. Zaha, Benteke, Andros Townsend, Jeffrey Schlupp and Jordan Ayew are all proven in the top flight and you could argue that they were the difference against the teams in the relegation zone, who were often newly promoted from the Championship.

That's all without mentioning Eze, who had a massive impact on how the team went about attacking. Crystal Palace used a mixture of 4-4-2 and 4-3-3 last season. In the 4-3-3 Eze played more centrally, allowing him to get closer to Zaha and take some of the defensive attention away from him.

Eberechi Eze was directly involved in 10 league goals last season - scoring four and assisting six

AB: It's been pointed out there are issues with the age of the Palace squad and many contracts running out this summer. Where do the club need to strengthen?

AH: Like every team in the division, Palace are searching for a goalscorer. As mentioned earlier, Benteke found the net regularly for the first time since 2016-17.

They have tried many different options to find the answer to this, most recently re-signing Michy Batshuayi on loan from Chelsea - though that deal didn't work out for him or the team this time. They also brought in Jean-Phillippe Mateta from Mainz but, apart from an eye-catching finish against Brighton, he wasn't used enough to judge.

There is a big drive to bring down the average age of the squad and sign more players in a similar bracket to Eze and Nathan Ferguson, who are 23 and 20 respectively. However, both of them are out for six months with injuries.

The majority of players who were coming to the end of their contracts are now officially free agents, so Vieira could have to entirely rebuild the squad. At a time when finances are tighter than usual because of the coronavirus pandemic, that would be a huge task.

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