Lumping doubles and singles into one win-rate number is the most common mistake amateur trackers make. They're different sports.

Why singles stats don't translate to doubles

Court coverage is shared, so unforced errors come from positioning, not just shots
Serve dominance is much higher — holds are easier
Returns matter less individually, formation matters more
Net play is constant in doubles, rare in singles

What to track in doubles specifically

First-serve return-in % — if you can't get returns in, your team can't break
Net-point win % — when you're at the net, do you win the point?
Partner consistency — track which partners produce the best results

What singles-only metrics tell you

True hold and break ability without partner influence
Stamina and rally tolerance
Mental performance in tiebreaks and deciders

In Tennis Log, always set the format field correctly when logging. Then filter by format in the Stats tab — your doubles win rate and singles win rate should be analyzed completely separately.