Fritz made headlines at the turn of the century for defeating Garry Kasparov and World Champion Vladimir Kramnik. Now, Fritz 17 introduces Fat Fritz — a neural network trained solely through self-play, in the tradition of AlphaZero — which defeats all traditional engines and even LCZero in direct comparison. Fat Fritz requires a high-performance Nvidia GPU to reach full strength, but represents the first genuine breakthrough in chess programming in years. The moves it suggests during analysis are often strikingly human and forward-looking. Opening theory is already beginning to change. A chess program for serious players.