Deep Tactics, 12 million checkmates, 156,000 tactics puzzles-both the largest in the world, with how to use video & beginner to master program(combo 1). Add to that the worlds largest database collections of 6.2 million games and the world champions annotated game collections in combo 2 and you have a great chess value. Add to this the massive 120+ chess book and ending collections on combo 3 for an incredible value!