The Ruy Lopez is arguably the most classic of chess openings. White immediately starts the battle for the centre, fighting for the initiative. This strategic clarity has made the Ruy Lopez, or Spanish Opening, an eternal favourite with chess players at all levels. Inevitably, this popularity has also led to a wealth of opening theory. In this book, Fabiano Caruana takes you by the hand and lays out a complete and practical White repertoire for club players. He avoids complicated chaotic lines, but doesn't shy away from sharp battles. Caruana loves to find and use the tactics to punish Black for risky choices. This one-volume and crystal-clear repertoire covers fifteen main variations, from the classical lines to the anti-Marshall (8.a4), and from the Schliemann (3…f5) to the Modern Steinitz. In an easy-to-grasp manner Caruana explains general characteristics, such as permanent weaknesses long-term goals, and is always looking for an advantage for White. The insights of the World #2 in this classic opening, will not only greatly improve your results in the Ruy Lopez, but also sharpen your general chess knowledge.
The book is full of ideas, not just moves. Caruana frequently talks about his games, as well as about games played recently by other top players, which is awesome (e.g., "I played this position against Magnus Carlsen and you wouldn't think..."; "Maxime Vachier-Lagrave usually plays..."; "Aronian - again! - was playing..."). And he explains the positions in the variations, outlining both the short- and long-run plans and ideas. He notes, for example, why the black bishop is often misplaced on b7 in the anti-Marshall ("[It] very often wants to get back to e6 to neutralize the white bishop on b3"), and he outlines why fixing Black's pawn on a6 creates a long-term weakness ("...right now, it might sound a bit funny to call this a weakness. But in a lot of endgames, this weakness will start to tell."). Similarly, in the Berlin, Caruana explains how one of the advantages that White often gets is Black's misplaced knight, either on c6 or d6, depending on the variation (e.g., "If Black's knight were on g6, instead [of] on d6, then Black would be completely comfortable"). In the Schliemann, he notes White's long-term, pawn-push plan when Black castles queen-side ("I recommend this plan of going for b2-b4. It is a very caveman approach to the position."). And in the Cozio, Caruana outlines the long-term problems created by moving the f-pawn ("Black won't notice the weakness of having played ... f7-f5 in the very short term."). All around, this is a great albeit brief book - a super solid, accessible introduction to the main lines of the Ruy Lopez.
I mean it's Caruana. It is just quality top tier analysis. And it fits together smoothly with plenty of options to deviate if you don't like the main recommendations.