I'll make this really short & sweet!
How about having three-way scoreboard reflecting the separate scoring-ranking catagories, i.e;
1) Total (as the scoring currently exists - including all modes of play)
2) Standard (Scoring and Ranking for single games only)
3) Team (Scoring and ranking for doubles & triples games only)
This way, for example, when you play a singles game your "Team" ranking wont be affected, only your "Standard" and "Total" ranking score would be. Or when you play a team game, your Standard score and rank would remain the same? Ultimate goal for some, then, might be to become a general in all 3 catagories.
Hope I explained this ok. Head isn't working real clear this am! lol