Only a handful of current Premier League managers significantly improved their team's fortunes in their first 12 months in charge.
Just eight of the division's 16 managers to have been in their jobs since before the end of last season managed to improve their side's win ratio by 10 or more percentage points in their first 12 months in charge compared to the 12 months before their appointment.
For managers who haven't been in their job for 12 months their whole tenure to date was considered.
The biggest improvement in win ratios was experienced by Norwich's Alex Neil.
The Canaries won just 30 per cent of their games in the 12 months before Neil was appointed in January this year.
Since then though they have managed to win 63% of their games. It should be pointed out though that the period before Neil was boss included 18 Premier League games compared to just six with him in charge.
Eddie Howe and Bournemouth have seen the next best improvement in win ratio, with the club going from winning 29% of games to 60% of games in the 12 months before and after Howe's appointment.
Jose Mourinho has made a positive difference since returning to Chelsea, although they are only six per cent better off than they were without the Special One.
Crystal Palace's win ratio has gone up from 31% in the 12 months before Alan Pardew took charge to 54% since then, an increase of 23 percentage points.
West Brom won just 21% of their games prior to Tony Pulis' arrival at the club. They've won 40% of them since then though, an increase of 19 percentage points.
Stoke's win ratio improved from 21% to 36% in the 12 months either side of Mark Hughes' appointment, while Manchester City's went from 56% to 70% in Manuel Pellegrini's first 12 months.
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Aston Villa saw an increase of 13 percentage points under Tim Sherwood (25% to 38%), while Everton's went up 11 points from 44% to 55%.
Three current Premier League managers to have been in charge since before the end of last season saw drops in their team's win percentages in their first 12 months compared to the previous 12 months.
Tottenham won 57% of their games in the 12 months leading up to Mauricio Pochettino's appointment but just 51% in the following 12 months.
For Liverpool the drop was from 47% leading up to Brendan Rodgers' appointment compared to 46% in his first 12 months at the club.
That's the same percentage point drop as Manchester United experienced in the first 12 months of Louis van Gaal's reign compared to the previous 12 months, going from 53% to 52%.
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