Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Just requires proper practicing

The title suggests you will play better tennis in 2 hrs, which is true. It depends on the level of player you are. For a beginner you will learn a lot from this book quickly because you do not have any ingrained techniques.As an intermediate player, it took a little longer to implement the techniques described in this book.I did learn from this book more once I practiced as directed in the book.I recommend doing the drills in this book to adopt the techniques, rather than just trying the techniques straight away in a proper match (like I did).I found the author to be repeating himself a lot in the book on certain points, but this could be because those points are the crux of his methods, and he is trying to instil these into his readers.There were fewer drills in the book than I expected, but each of them are quite useful.I would recommend this book, with the reader to allow for proper dedication and practice time to adopt the techniques.