There's been some chatter these past couple of weeks about Dimitar Berbatov's perceived decline, with Bryan Ruiz's absence being suggested by a number of sources as the main factor. Fantasy Football Scout members can read their well reasoned and logical take on the issue here. This post is not a rebuke to that or any other post - indeed Ruiz's absence might be a legitimate reason for Berbatov's apparent decline - I just want to highlight the danger of cherry picking stats and using small sample sizes to make data fit with a convenient narrative.
Using just the last three games without Ruiz seems to be a touch imprecise as we have a number of other gameweeks from this very season where Berbatov played without his Costa Rican pal (GW3, 4 and 8, plus two games where Ruiz only came on a sub - GW5 and 9). Looking at Berbatov's data simply split between those minutes with Ruiz and those without gives a closer situation than the disaster some have suggested, but we still observe a not insignificant difference in Berbatov's underlying stats:
So while Berbatov has gotten as many touches without Ruiz in the side, he hasn't been able to generate as many shots, with almost a full shot inside the box and 0.6 shots on target less without the Costa Rican. Those totals aren't insignificant when you consider that around one in three of those SoT are converted into goals.
The question I have though is one of causality. Correlation does not necessarily imply causation and thus we need to consider if Ruiz's absence was really the leading factor in Berbatov's 'struggles' these past three weeks. One of the metrics I use to determine team strength is how they performed against their opponents to date compared to others in the league. So if Arsenal are scoring an average of nine shots inside the box and Everton hold them to six, we'd say they overachieved by 50%. Averaging those +/- factors over the season gives us an overall rating with which to judge teams by. If we split Fulham's opponents to date between those who are above or below average, we get the below results for Berbatov:
The non-statistically swayed reader will now say "thanks for telling us that Berbatov is better against weaker teams" but yet this simpler narrative seems like at least part of the explanation for the Bulgarian's apparent decline. He's faced five 'hard' opponents this season, who have all performed between 11-26% better than league average, with three of those coming in the last three gameweeks. Stoke (-21%), Chelsea (-11%) and Tottenham (-26%) have all held opponents to at least 11% less shots than league average and thus Berbatov's chances have dried up somewhat. The next six gameweeks see Fulham face five sides who have either been average or worse this year in terms of allowing shots, with only the trip to Anfield in GW18 looking like a particular concern.
Could Berbatov be missing Ruiz? Possibly. Even probably. But I'd be cautious about taking a three-game, non opponent adjusted sample and trying to fit it into a single narrative to explain the variance in his underlying stats. If you own him, I would suggest it's hasty to sell now given the upcoming fixtures and I personally want to see how he fares against lesser opponents in Newcastle and QPR before pronouncing his demise as terminal.
Using just the last three games without Ruiz seems to be a touch imprecise as we have a number of other gameweeks from this very season where Berbatov played without his Costa Rican pal (GW3, 4 and 8, plus two games where Ruiz only came on a sub - GW5 and 9). Looking at Berbatov's data simply split between those minutes with Ruiz and those without gives a closer situation than the disaster some have suggested, but we still observe a not insignificant difference in Berbatov's underlying stats:
The question I have though is one of causality. Correlation does not necessarily imply causation and thus we need to consider if Ruiz's absence was really the leading factor in Berbatov's 'struggles' these past three weeks. One of the metrics I use to determine team strength is how they performed against their opponents to date compared to others in the league. So if Arsenal are scoring an average of nine shots inside the box and Everton hold them to six, we'd say they overachieved by 50%. Averaging those +/- factors over the season gives us an overall rating with which to judge teams by. If we split Fulham's opponents to date between those who are above or below average, we get the below results for Berbatov:
Could Berbatov be missing Ruiz? Possibly. Even probably. But I'd be cautious about taking a three-game, non opponent adjusted sample and trying to fit it into a single narrative to explain the variance in his underlying stats. If you own him, I would suggest it's hasty to sell now given the upcoming fixtures and I personally want to see how he fares against lesser opponents in Newcastle and QPR before pronouncing his demise as terminal.
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