“Some people claim that receiving a red card pushes ‘you´re team’. I want to find out if it is me who is trying harder in this moment or if there really is some kind of ‘disadvantage’ / ‘advantage'”
(– xtoonator on Reddit)
The post in question was written by a user called xtoonator. If you are one of our regular followers, you may recall that we looked into his handicapping experiment on another occasion. This time, he is trying to verify a different and yet somewhat similar claim: That getting a red card gives you an advantage or a boost rather than a disadvantage.
We don’t know whether xtoonator actually managed to collect any data for his red cards experiment, and hence, whether there was a conclusion. We would like to add that the method suggested by him suffered from a number of fundamental issues, including a serious issue with the sample size.
As for the actual claim that red cards gives your team a boost, there are easier, more reliable and more valid ways to test it.
How to test the red card boost hypothesis in a proper way
If there is a red card boost, players, who receive red cards, will win more matches and lose fewer. If a red card boost exists, players who received a red card, will be more likely to score, meaning that they increasingly (a) will be able to win matches, which under normal circumstances would have been draws, and (b) turn 1-goal defeats into draws.
Do players, who received red cards, win more matches?
The obvious place to look for an answer to this question is in our huge match history sample, which contains data on red cards for both the involved players. This allows us to check whether the guy with the highest number of red cards did go on to win in the majority of the cases.
These are the results from our latest sample:
- Matches in total: 1094
- Matches containing red cards: 136
- Matches where the winner had more red cards: 29
- Matches where the winner had fewer red cards: 87
- Matches containing red cards which ended in a tie: 20
Our sample is big enough to confirm that having a red card gives you a clear disadvantage. At a p-value of ~0.0001 (confidence level 95 %), we can firmly reject the hypothesis that a red card gives you an advantage.
In addition to that, our data indicates that players, who received a red card, not only lost three times more often: Their ability to draw also decreased: 18 % of the matches, that didn’t contain red cards, ended as a draw. The corresponding percentage of the matches containing red cards was only 14 %.
Getting a red card not only reduces the chance of winning – it also reduces the chance of drawing.
A small anecdote
Crlarsen coincidentally played a single match against xtoonator during FIFA 15. Crlarsen managed to win by 2-1, in part due to that xtoonator received two red cards. Afterwards, xtoonator wrote this in a private message to crlarsen: “i know what you´re saying. but there was some kind of scripting. both red cards were bs, the penalty gave me the rest.”
It says it all.