100 percent not even a question. It's a major factor (100 elo ish) if you drastically change themes, in the short term. It pretty quickly normalizes. I imagine the optimal setup vs a "reasonable" one is like 25 pts once it has habituated. But yeah this effect is most pronounced when an online high rated player who has never played OTB, starts playing OTB. You can get like a 1600 losing regularly to a 1200.
Do board themes affect your performance?
well,when i play on lichess, i play significantly better .but when on chess.com i play much worse :/
well , The most important thing is to set a board and pieces than you are comfortable with. and also to visit regularly : @aquajewel">@aquajewel for useful Chess advises and coaching !
Yes when I see chess pieces that look worse than Sargon I's pieces on the Apple 2, yeah, that definitely affects my performance.
(Pretty sure Micro-chess 2.0 used the same pieces).
https://www.youtube.com/watch?v=jPNKXXZI6Q0