Mieses attained maturity as a player in 1895, just after turning 30, when he contested the 9th Chess Congress in Leipzig, followed by an exhibition tour in Russia and then a match with David Janowski.

Mieses was a dangerous attacker with a number of famous victories to his credit, e.g. against Frank Marshall (Monte Carlo 1903).

The octogenarian Mieses only won a single game against a 22-year-old opponent, but secured the brilliancy prize for a game-winning attack combination.

Three years later, at 84, he defeated the 86-year-old Dutch master Dirk van Foreest,[5] afterwards commenting "Youth has been victorious" and also gave a series of exhibition matches in western Europe.

His durability at an advanced age was attributed to his belief in physical fitness; he engaged in daily swims until almost the end of his life.

Mieses largely adhered to the 19th century Romantic school of play and showed little aptitude for positional chess.