A phrase I seem to hear constantly from football pundits when discussing the success of teams in the Premier League is ‘the rub of the green’. The phrase is commonly used in sports, particularly golf, to mean that teams need to get their fair share of good fortune in order to achieve success. While there is a lot more than luck which determines success in the Premier League, it is fair to say good fortune plays it’s part in helping teams go that extra yard. A team that I have constantly heard are not getting the ‘rub of the green’ this year is Sheffield United.
Despite finishing 9th last season, the Blades are currently rock bottom of the league with just one point to their name after nine games. I have heard many commentators say that Sheffield United are a good side, but they just don’t seem to be getting the breaks they got last season. While it’s nice to hear football pundits speak with a bit of sympathy for teams, I’m curious to see if there is any way to test whether United’s poor form this season is due to luck. The only statistic I could think to use that may act as a proxy for luck is the number of times team’s hit the woodwork i.e. the crossbar or post.
Hitting the woodwork can be seen as misfortunate because in the vast majority of cases it indicates that a player’s shot has beaten everything but the frame of the goal. Fair enough you could argue that hitting the crossbar is a failure in accuracy, but you really are talking about centimeters. In any case I think most players and fans would deem it unlucky if a player shoots at goal and beats the keeper only to be denied by the post. Therefore, the premise of this analysis will be to assume that each time a team hits the woodwork, they were denied a goal in an unfortunate manner which could’ve helped their points tally.
To test how this would impact on their points tally I have run a robust regression analysis on the relationship between goals scored by teams to date in this season’s Premier League and their points tally. For those not familiar with regression analysis, the results of this test basically tell me roughly how many points a team will accumulate for every additional goal they score. The value for goals scored is 0.87 which indicates that for every additional goal a team scores, they would accumulate roughly 0.87 more points. Now obviously a team can’t do this, you can only achieve 0, 1, or 3 points at the end of a game but this is just an analysis to show us the rough relationship between scoring and point accumulation over time.
Now if we take account of the fact that Sheffield United have hit the woodwork twice after nine games and we assume those shots would’ve lead to goals if they were more fortunate, then we could say that if they had the ‘rub of the green’ they would be 1.74 points better off. This still wouldn’t be enough to lift them out of bottom place and in addition to that they are far from the ‘unluckiest’ team in this regard. West Ham have already hit the woodwork eight times. What is interesting to note though is that last season, over the entire 38 games, Sheffield United hit the woodwork just three times, less than any other team in the league. Based on this metric you could consider them the luckiest team in the league last season.
This season however, they are only nine games in and have already hit the woodwork twice. Does this mean that there could be truth to the ‘rub of the green’ saying and that Sheffield are destined to go down because they have stopped being the luckiest team in the league?