It is not the quality of your best moves that wins you games; it is the quality of your worst moves. The quickest way to improve your chess skills is to raise the bar.The Spanish grandmaster and coach Jesus de la Villa has proven with his best-seller 100 Endgames You Must Know that he understands exactly what a chess student needs. Building on his experience as a writer and as a coach for juniors, he has carefully selected the 50 Mistakes every player should be aware of – so the mistake can be avoided. De la Villa loves this quote from the American First Lady, Eleanor Roosevelt: ‘Learn from the errors of others. You can't live long enough to make them all yourself.' For over a decade, De la Villa has closely observed the Spanish junior championships, noting the recurring errors that players make. He has taken notes, classified these errors, and created training tasks based on them. From this wealth of chess exercises, he has selected the most impactful and has added recommendations how to correct the error.Your performance will improve dramatically because this book offers you:•50 important chess lessons•detailed and lively explanations•clear summaries and recommendations•dozens of tests.