You could store the matches in a HashMap as well, using some MatchId type as the key, i.e., HashMap. Then you can use that as the reference in players: HashMap. Only downside is that you have to generate unique MatchIds, e.g., by using some counter.

Hmm, I didn’t think that out. Still better than hair though

Medusa. She makes me rock hard. Also, no hair in the shower drain is a nice bonus.