Are you still trying to figure out which budget defender to pick? Are you asking a question, which non-top-six teams are likely to get the highest number of clean sheets? Using statistics, I examined numbers of clean sheets of all teams from last three seasons (all teams which played all three seasons, so not promoted or relegated sides).
This article is very similar to my last one, where I examined the most “stable” and “unstable” players with the use of the Coefficient of Variation. In this one, I used the same technique to examine the most “stable” teams in terms of clean sheets.
In the table below, there is the list of teams sorted by the lowest value of the Coefficient of Variation of clean sheets. It is calculated from the number of clean sheets from last three seasons. The lower the coefficient, the lower the dispersion of clean sheets around the Expected Value (mean). Based on this, we may assume that in the next season teams with low Coefficient of Variation will more likely achieve the number of clean sheets close to its Expected Value.
For example, Leicester has the Coefficient of Variation 0,05. We may assume that in the next season the number of Leicester clean sheets will be very likely close to the Expected Value (mean) of their clean sheets from last three season: 9,33.
Manchester United has the Coefficient of Variation 0,37. Based on this, the number of Manchester United clean sheets in the next season will be less likely close to the Expected Value (mean) of their clean sheets from last three season: 14,33. It may vary in both directions: it may be much higher than the Expected Value but also much lower.
From non-top-six teams, the most stable teams (in terms of clean sheets) in last three season were Leicester, Watford and Everton. In the next season, they will likely get numbers of clean sheets close to the Expected Values. For Leicester it is 9,33 CS, for Watford 7,67 and for Everton 12,33. Those three non-top-six teams had really low volatility of clean sheets in last three seasons. On the other hand, it doesn’t say us anything about defensive qualities of these teams. Based on this, we can expect that Watford will achieve probably 8 clean sheets in 19/20 season. Is it enough to include Watford defenders in our plans? No. On the contrary. Despite the low value of the Coefficient of Variation, the Expected Value is very low. We have to look in the table for the combination of low Coefficient of Variation and high Expected Value.
From non-top-six teams, Everton looks the best defensively based on this statistic, because the Expected Value of their clean sheets from last three season is high and the Coefficient of Variation very low. Then it is Leicester and Burnley. If you are looking for a budget defender or a goalkeeper, I think you should focus on these three teams. Just to remind you, I did not consider lately promoted sides like Wolves, Brighton in this article because of lack of data.
Source: Official Premier League