A Rematch Button
LuTon
I think after a duel a rematch button should appear and if both parties press this, then a rematch takes place. This would especially be good on close games where someone wants to try at redemption.
However to avoid any foul play this button should be there only one time. After the rematch game has concluded the button should no longer be an option. So one rematch game is allowed duel paring.
ch1v4lry
I think the rematch button is okay to stay to allow multiple rematches — for example, chess.com has it and even allows "friendly games" (as in you can directly challenge someone else) for rating, and I don't think it's a huge problem there. But I might be wrong, so please correct me if I am.
LeWixx06
but imho the rematch should be unranked