Manchester United bounced back with aplomb last night after what was argued to be one of the greatest ever Premier League upsets. Their loss to Sheffield United was definitely a surprise, particularly given that this was a top versus bottom clash at the time. That said, anyone watching Sheffield United would see that they are not playing that badly (they are fourth from bottom on the attacking xG table). Both teams were arguably in somewhat of a false position at the time of the match.
How does this loss to Sheffield United compare to other famous upsets? One way of considering upset objectively is to use implied probabilities from bookmakers odds (adjusting for the bookies take). These are useful as they account for contextual factors at the time of a match.
The table below considers upsets in recent Premier League history where there is a single source of odds data. Some more famous upsets are left out (Bradford City 1 - 0 Liverpool - May 2000, Liverpool 0-1 Barnsley - November 1997). The percentage indicates the adjusted probability of the underdog winning.
United's recent loss only comes in ninth in the list. Interestingly, a home win tops the list as – market odds suggested that Norwich only had a 4% chance of winning at home to Manchester City last season. The second biggest upset was the Manchester United 2-3 loss to Blackburn in 2011. While this shares an upset probability with the next two fixtures on the list, the second criteria I have used is the draw probability (i.e. Blackburn’s chances of a draw were lower than Crystal Palace and Hull’s)
So, in the David vs. Goliath battles over the recent years, the Sheffield United recent win was definitely high on the list but probably not the greatest Premier League shock ever. For now, this belongs to the Canaries.