The abstract is really unimpressive. The effect was not statistically significant. Was it even positive?* It is only by throwing out games lost on time that they find improved performance. Systematically throwing out games lost and finding a lot of games won is a standard error. Did it improve the moves they made, or did it cause them just to ruminate on lost games? They could have tested this, asking computers how good the moves were, but I don't think that they did. Even if the moves were better, was it because of the drugs, or because of the additional ... (Read more)(Click to expand thread. ⌘F to Expand All)Cmd/Ctrl F to expand all comments on this post
Addendum: Stimulants mess with your sense of time. Time management is an important part of playing chess, but surely players don't do it by looking at the clock, but by heuristics about how much to think, heuristics that could be messed up by their sense of time. So I think that the time management would be improved by practice with the drugs. Most chess players probably have practice at varying levels of caffeine, so the study is a more fair comparison of that drug than the others.
Added later: Indeed, caffeine lead to fewer losses on time than modafinil ... (Read more)(Click to expand thread. ⌘F to Expand All)Cmd/Ctrl F to expand all comments on this post