The Last Checkmate by Gabriella Saab.

Maria Florkowska is many things: daughter, avid chess player, and, as a member of the Polish underground resistance in Nazi-occupied Warsaw, a young woman brave beyond her years. Captured by the Gestapo, she is imprisoned in Auschwitz, but while her family is sent to their deaths, she is spared. Realizing her ability to play chess, the sadistic camp deputy, Karl Fritzsch, decides to use her as a chess opponent to entertain the camp guards. However, once he tires of exploiting her skills, he has every intention of killing her.