By comparing their own results with the optimal result
Chris Ward covers three offbeat but important defenses to this ancient opening
Grandmaster Daniel King on his YouTube channel:
open rook lines
“I absolutely love it
Reek, van: Grand Strategy Strategie By comparing their own resultsUsing many extensively documented Spassky games, the author provides great learning material from relatively simple plans, wonderful combinations to stubborn defenses. Spassky's opponents in this book include Smyslov, Karpov, Bronstein, Kasparov, Fischer, Timman, Keres and many other important top players. A very interesting book, written with the support of Boris Spassky. Figurine Notation, 144 pages, 2000, paperback, English.