Come si scrive correttamente "matchup" o "match-up" in italiano?

In Russian, this word hasn't yet settled into one correct form, because the borrowing is very recent. In dictionaries, the rules for writing foreign words don't always work, especially for young slang. So the question of what's "correct" is a bit more complicated than it seems.

If we're talking about tendencies, borrowed words from English in Russian are usually written as one word if they've already taken root - nobody writes "sayt" with a hyphen, right? The logic is the same: "matchap" is one concept, one term, so writing it as one word looks more natural. People often use a hyphen when they're still thinking about compound English words (match-up), but in Russian that's unnecessary.

I'd advise writing it as one word - "matchap", like most other borrowed words. If some publication or community uses a different spelling, then stick with their style in that context, but overall the single-word version is considered more correct.