Insight Corner: The data behind the 'new manager bounce'

In the latest edition of Insight Corner, our new column that leverages insights from our GeniusIQ-powered Performance Platform, Andrew Clausen explores the phenomenon of the 'new manager bounce' - drawing on current examples in the Premier League and EFL Championship.

Let's discuss the new manager bounce. I think the new manager bounce is very much a thing. We see a new manager come in and change the fortunes of a team at least a couple times a year. It's also not a sure thing: just ask flailing Leicester City and Southampton.

But there is a more interesting question at the heart of the new manager bounce: Do managers actually make a team better mid-season, or is it just variance? Across English football, there are currently a handful of examples that will help us scratch the surface of this question. In the Premier League, there's Everton, and in the Championship, Coventry City and Plymouth Argyle are great test cases.

Let's take a data-driven look at each.

David Moyes replaces Sean Dyche

If there's a data-driven case for replacing your manager mid-season, this might be it.

Moyes has not only seen results improve, but every metric improve my orders of magnitude, including those not listed below, like goals conceded per game (20% fewer) and most notably goals scored per game (a staggering 157.3% increase).

It's a small sample size, so there's a caveat. But it's fair to say Moyes has overseen actual improvement at Everton.

Conclusion: Notable Improvement

Frank Lampard replaces Mark Robins

Lamps is finally making his mark as a coach! Right? Well, not entirely.

While they have seen a turnaround in form, the underlying numbers tell a different story. While goals scored and goals allowed have improved under Lampard, xG has gone down, and xG conceded is only marginally better. This has actually resulted in a drop in xG difference per game.

Ironically, Coventry's goal difference per game is basically equal to what their xG difference per game was under Robins. It certainly seems like Lampard stepped into a team that had been playing well, but wasn't getting the bounces they needed.

Conclusion: Variance Bounce

Miron Musli? replaces Wayne Rooney

Wayne Rooney the coach is not Wayne Rooney the player... let's just leave that there.

Obviously, given recent results, Musli? has improved the team. Again, though, it's not that straightforward.

He arrested their horrendous defence, and has pushed them off the bottom of the table. But their attack, which was already very bad, has gotten worse. They're scoring basically the same amount per game (a less than 1% change), but they're actually generating less xG.

So should the new manager be praised for fixing the defence? Is the downturn in attack a major issue? It's all a matter of perspective.

Conclusion: Inconclusive

While Moyes appears to be the most clear-cut success, it's hard to tell for certain whether the drastic improvement will sustain beyond this season. For Coventry and Plymouth, the results are murkier, and may well depend on how they each finish the season.

If Coventry make the playoffs, and Plymouth survive relegation - both unthinkable outcomes when their previous coaches were dismissed - we'll undoubtedly praise the new manager bounce. But whether either team has actually improved as a result of the change, will be a debate for another day.