Baduk is the korean version of the board game Go. Expert players of it have below-average IQs on average.
“However, Baduk experts demonstrated slightly lower IQs than did controls (mean ± SD, 93.19 ± 10.42 for Baduk experts, 101.21 ± 13.11 for controls; t = −2.016, df = 32.910, p = 0.052) as estimated by the Korean version of the Wechsler Adult Intelligence Scale (K-WAIS) (Kim and Lee, 1995), and a significant difference appeared between the two groups for level of education”
Baduk is the korean version of the board game Go. Expert players of it have below-average IQs on average.
source
Gwern said the same is true of chess but I don’t have a source for that.