Chess has evolved significantly over the past few years. Talented teenagers are playing better than ever, top players possess even deeper theoretical knowledge and make fewer mistakes, and preparation now demands more time and energy. Consequently, winning against strong opponents has become increasingly challenging. This has taught us that players need to manage their energy levels carefully. Most of the advice in this book remains applicable even when you are tired, though in such cases, it's usually better to play more solidly if you're primarily aiming for a good result.  That said, results aren't everything. Interesting games are also important, and we are excited to share them with you in this epic book.