Is switching your first move often, just to stay unpredictable, a mistake?
These answers restate the rules implemented by our open-source engine, which follows the WXF laws and is regression-tested against the official 110-diagram repetition casebook. Where an answer refers to a specific position, that position lives on the linked reference page, where the build verifies it against the engine before publishing.
Direct answer
Usually, yes, below a strong level of play. Unpredictability sounds like an advantage, but for most players it rarely pays off enough to offset the real cost: losing the depth of understanding that comes specifically from reaching the same kinds of positions again and again.
Why depth beats surprise for most players
The value of an opening comes from understanding the middlegame it produces, and that understanding is built through repetition, not through variety. A player who has played the same system fifty times has a real, earned sense of its typical plans that a player who changes every few games simply cannot have, whatever the short-term surprise value of variety might be.
Where some variation is genuinely reasonable
Having two or three well-understood systems rather than exactly one is fine and normal, as covered in how many openings you actually need; the problem is treating every game as a chance to try something new rather than deepening what you already have. Variety within a small, understood set is very different from constant switching.
Related questions
Does this change once I am a strong, experienced player?
Somewhat; players with deep repertoires can afford more variation because their understanding of each system is already solid.
Is trying new openings in casual games still worth doing?
Yes, casual exploration is genuinely useful; the caution here is about your serious, rated repertoire specifically.
.