François-André Danican Philidor was both a chess and musical prodigy. He was taught chess by Kermur Sire De Legal, who initially gave him rook odds, until the young Philidor became too strong for his teacher. This book was the first chess book to explain the openings the middle game and the general strategy of chess. The book claimed that “Les pions sont l’âme du jeu”, a phrase that became widely known as “the pawns are the soul of chess”, a maxim known to chessplayers ever since.
In this position from yesterday's key encounter in the Candidates Tournament, GM Fabiano Caruana, current world #3, has just played 103. Kc4! to reach a winning position against GM Peter Svidler. Unfortunately he was not on top of the latest theory, having failed to study Philidor's 1749 book, and only drew the game.
Well, that's the 21st century for you. It's just too hard to keep up with everything. _______________________
[Update, Mar 28 2019]
Whadaya know. Exactly three years later, Caruana got the same ending yesterday as black against Gareyev in round 7 of the US Championship. After 121 moves, Gareyev made a slip, and this time Caruana knew his Philidor. He pounced and took the full point.