Chess Puzzles vs Echo Ramsey

Turn every puzzle into progress. Train with 5M+ puzzles from real games, personalized to your level. When you make a mistake, understand why - and learn from it. That’s the idea we built this app around. Solving more puzzles is useful, but we wanted training to be about more than getting a position right or wrong. We wanted every puzzle to teach you something - about the move you missed, the pattern you didn’t recognize, or the way you calculated the position. There are more than 5 million puzzles from real games. But the number itself isn’t really the point. What matters is finding the right positions for you, at the right difficulty, and helping you learn from them. When you make a mistake, you can understand why. Use hints, explore better moves, get coaching, and look deeper into the position instead of simply moving on to the next puzzle. Over time, your training starts to reveal which tactical patterns give you the most trouble. You can practice across 64 motifs and patterns - forks, pins, sacrifices, checkmates, endgames, and many more - and spend more time on the ideas that need it. You can also see how your training develops over time: your rating, accuracy, training time, and performance across different patterns. And when you’re ready for something truly advanced, there are more than 300,000 composed chess problems from solving competitions. They’re difficult, precise, often beautiful - and solving them can be one of the most satisfying forms of chess training. We’ve also tried to make this a place you’ll actually want to come back to. Solve a few puzzles when you have five minutes. Sit down for a longer session when you feel like training seriously. Build a streak, reach a milestone, or simply keep showing up. Whether you’re new to tactics or have been playing chess for years, the goal stays the same: Learn something from every puzzle. Play better chess. And we’re here to help you along the way. Privacy Policy: https://chess.phd/privacy/ Terms of Use: https://chess.phd/terms/

Echo is a puzzle game built on real open problems in mathematics. Each puzzle is a graph: dots joined by red and blue lines. Your job is simple to learn. Tap a line to flip its color, and break up the "bad cliques" - groups of dots all wired together in a single color. Clear them within your move budget and the puzzle is solved. Here is the twist. Every puzzle is a slice of a genuine research graph, and every solution you find is committed to a shared, growing proof tree. When you solve, your result seeds a brand new puzzle for another player. Their solve seeds the next. Together, the whole community is searching for colorings no person and no computer has ever found. You choose which problem to work on from the home screen: - R(4,4), the practice board - solved long ago, so the search genuinely finishes and you can see the whole engine work end to end - R(4,6), the frontier - an open problem where reaching zero would set a real new record - R(5,5), the legendary one - open for decades, where the prize is the lowest count the network has ever driven it to You do not need to know any of that to play. If you can spot a pattern and tap, you are already contributing. FEATURES - Quick, tactile puzzles you can finish in a minute - Three problems to play, from a winnable warm-up to a famous unsolved one, switchable any time - Five ways to view each graph: circle, spectral, matrix, hub, and density - switch any time to see the structure differently - A living progress screen showing the community's best reach and the proof tree growing in real time - Your lineage: see how many puzzles your solves have seeded for other players - A built-in glossary that explains every term in plain language - No ads, no timers, no pressure Color the graph. Advance the proof. Echo forward.