There was an article earlier this week on HN about the effects of stimulants on Chess Ability that was oddly consistent with this: https://worldchess.com/2017/0

There was an article earlier this week on HN about the effects of stimulants on Chess Ability that was oddly consistent with this: https://worldchess.com/2017/01/25/special-report-new-study-finds-performance-enhancing-drugs-for-chess/ https://worldchess.com/2017/01/25/special-report-new-study-f... In particular, players would tend to lose on time more often when taking stimulants. When framed from the perspective of this article, that effect becomes "obvious".