How did solo whist differ from partnership whist?

Solo whist differs from traditional partnership whist primarily through its bidding structure and the absence of fixed teams.12

In partnership whist, four players are divided into two permanent teams. The game focuses on capturing the most tricks, with scoring based on "odd tricks" (those beyond six) and sometimes "honours" (specific high-ranking cards in the trump suit).2

In contrast, solo whist is a nonpartnership game where each player acts independently. Key differences include:1

• Bidding: Unlike partnership whist, where the trump suit is determined by the last card dealt, solo whist features a competitive bidding process. Players bid to fulfill specific contracts, such as winning a set number of tricks (Solo, Abundance, or Slam) or losing every trick (Misère).1
• Alliances: While primarily an individual game, solo whist allows for temporary alliances through the "prop and cop" bid, where one player proposes a contract and another may accept it to become partners for that specific deal.1
• Scoring: Players pay or receive points based on the success or failure of their individual contract, rather than a shared team score.1