Why Carrick may not be shoo-in for Man Utd job

ByChris Collinson

BBC football data analyst

Manchester United have won the most points in the Premier League since caretaker boss Michael Carrick took over in January, so it seems a no-brainer to give him the job on a permanent basis.

But dig a little deeper and the decision is not so obvious as the stats warn that, as brilliant as results have been, they're unlikely to continue in the long run.

On the surface everything looks hunky-dory under Carrick.

As well as his side taking the most points during his tenure, only Arsenal have a better goal difference, with no team scoring more goals.

United's attack has been running blisteringly hot under their former midfielder, which is obviously fantastic in the short term, but slightly worrying for the future when it inevitably cools down.

Eight teams have been better at creating chances based on expected goals, but having the best shot conversion rate in the league means United have scored seven more goals than a team historically would from the chances they've had - more than any other side.

Looking at attack and defence overall, the only side to have overperformed their xG numbers by more than United since Carrick took charge are Nottingham Forest, who are enjoying their own 'new manager bounce' under Vitor Pereira.

Of the six players who've been the most clinical in the Premier League since Carrick took over in mid-January, three of them play for his team.

Only Forest's Morgan Gibbs-White has been more ruthless with his finishing than Matheus Cunha, while Benjamin Sesko and Casemiro have also been enjoying a hot spell in front of goal recently.

While Carrick deserves credit for getting his players firing, will the six players below remain the best finishers in the Premier League forever? It's unlikely.

If we compare United's stats under Carrick with those under Amorim earlier this season, we can see that improving the team's efficiency in both boxes is what has brought about such an upturn in results, perhaps due to his man-management of the players.

Not only have United's attackers been efficient under him, but goalkeeper Senne Lammens has too, with only Bournemouth's Djordje Petrovic (5.8) and Forest's Matz Sels (3.2) preventing more goals than expected, given the shots they've faced, than the Belgian keeper since Carrick took charge (2.8).

But it's also true United have dominated games less than they did under Amorim, taking two shots fewer per game under Carrick and conceding slightly more.

That's not actually that damning as it's worth remembering United were doing quite well when their Portuguese boss was sacked as they were sixth in the Premier League, level on points with fifth-placed Chelsea and just three behind Liverpool in fourth.

But while results have improved significantly under Carrick thanks to how 'hot' the team have been at both ends of the pitch, overall performances have not been as impressive under the caretaker boss when it comes to the basics of creating more, and better chances, than their opponents.

The reason why this is so important is that history clearly shows the more a team dominates their games (measured by their xG difference), the more success they have in the long run.

If we look at the 200 teams that have played in the Premier League in the last decade, we can see the ones with the best xG numbers win titles, while teams with the worst get relegated.

We've even seen how results of teams eventually fall in line with their underlying numbers over the course of this season, with early overachievers Aston Villa and Sunderland.

Thanks to some excellent long-range finishing from Villa players and Black Cats keeper Robin Roefs being the best shot-stopper in the league, both sides defied their xG numbers to sit high in the table at the halfway stage, with Villa third and promoted Sunderland seventh.

But as the season has gone on, fewer of Villa's shots from range have found the net like they did before, while Sunderland's Dutch keeper has had a more difficult time.

So while the overall performance of the team has stayed mostly the same - or even recently improved for Sunderland - results have been worse over time as their xG-defying exploits have come to an end.

Just as the fantastic results shouldn't guarantee Carrick gets the job, these cautionary underlying numbers shouldn't necessarily prevent him from getting it either.

After all, bringing a crop of new players in this summer could potentially allow him to implement a new tactical set-up that could lead to improved performances.

But what theses stats do tell us is that if performances continue like they have under Carrick next season, then results will eventually get worse, the good vibes will dissipate and the club could well be looking for yet another new manager before the end of the campaign.

The owners of Manchester United therefore have to avoid being simply taken in by results and fully evaluate whether the 44-year-old has the potential to lead such a prestigious club forward in the long run.