RSSSome thoughts
Verbal abilities differ from mathematical abilities. Men and women display this, with scores of verbal intelligence being roughly the same, and STEM scores in men showing Greater Variability, hence longer tails, and hence almost all of the top scientists are men. This same pattern could be present between races.
The lower average levels of neurosis in blacks could be a factor as well. That would make one better at games, which require a degree of improvisation and action under time pressure, favouring those who are able to enter flow-states faster, which blacks on average would be, due to lower inhibitions from the prefrontal cortex.
In the prior article about school performance in Britain, I noted that the high-scoring children were Nigerian girls. School being an activity that at least partly relates to conformity and obedience, it’s unsurprising that girls would excel there. Most women’s intelligence being average or closer-to-average, it’s unsurprising that we should find them succeeding in British schools. Such a statistic would hide any endemic lack of STEM ability among Nigerian male populations, but the long-term real consequences of that would be evident in economic outcomes, which they are. Adding to that the possibility of cheating raised by an earlier commenter (a practice at which many Nigerians wouldn’t bat an eyelash) and you have reasonable doubt.