[wrsh07]

I think Zach Gage (developer of excellent games including Really Bad Chess, Spelltower, etc) says on Adam Conover's podcast that for many people they have difficulty improving at a skill when they have time (or other) pressure

Thus, he always includes a relaxed mode to let someone practice without any stress. Incidentally, he realized that some people only ever play in the relaxed mode!

[lobsterthief]

Related: Great new Freakonomics podcast about why we do poorly under pressure[0]

[0] https://freakonomics.com/podcast/choking_radio/