Why did whist become a leading intellectual card game during the 19th century?

During the 19th century, whist became the premier intellectual card game of the Western world. Its reputation as a sophisticated, scientific pursuit was largely defined by the fact that all four hands remained hidden during play, which required players to rely on skill, memory, and deduction rather than visible information.12

This emphasis on hidden information created a challenging environment for analysis and strategic play, which enthusiasts considered far more intellectually rigorous than later games like bridge. Because players had to guess the distribution of cards, the game stimulated deep study and the development of complex systems of play. Even as bridge began to gain popularity toward the end of the century—offering more clarity through the exposure of a "dummy" hand—many dedicated whist players initially resisted the change, arguing that the inherent uncertainty of whist made it the superior test of a player's intellect.2