Another option is to take on additional objectives, which serve to handicap you.

For instance, when competing to win, there's little room to be exploratory, playful, envelope pushing, maximizing learning. First tries at anything mostly fail. So I'll say "I'm going to focus on learning new things, not just on winning". And verbalize the exploration like "hmm, I wonder if...", attempt, and post mortem review ("I just tried X... and Y happened"). Or offer that as an option - "I'd like to try throwing (at target) under my leg... or would you rather I throw regular?"

Play to teach can be mixed in as a part-time objective. "Fake-oops, I dropped my card face up. What was it? What's something you might do differently knowing I have that?"

One can also optimizing for game interesting / fun. "Well I could use this card to wipe you out there, instead of discarding it, but this is so much fun, I want to fight it out".

So never "illusionary success", always transparent honesty. But being explicit that there can be more than one "game" at play. But also have to watch that this all doesn't become an "it's unpleasant to lose" avoidance strategy - if playing "for real", maybe that's to the bitter end.