According to Wikipedia, under “List of association footballers who died while playing“, in 2001-2020 there was an average of 4.2 deaths per year attributed to SCD or SUD, the vast majority being SCD. In contrast, in 2021, according to our list, there were 21 cases of SCD/SUD among FIFA players. In other words, instead of 4 SCD/SUD deaths per year (according to Wikipedia data), or 5 cases per year (calculated according to the BMJ) during 2001-2020, 21 players have died so far this year.
That is, about 5 times more than the annual average!
This figure is found to be statistically significant. In fact, there is no other year since 2001 where the difference between the number of observed cases of SCD/SUD and the expected number is statistically significant.In 2021 it is highly statistically significant and only likely to happen by chance about 2 in 1,000 times.