ChessPuzzle.net version 3 update progress

I have been working on version 3 of ChessPuzzle.net for a while now, and I am happy to announce further progress.

As announced in a previous blog post, the puzzle algorithms for version 3 include the following benefits:

• Integration with Neural Network-based Stockfish versions
• Support for calculating multiple reply moves, and displaying them on the solution page
• Improved opponent moves

These algorithm updates have now been extended to all remaining puzzle types. Most puzzles have now been updated to the new format and recalculated using modern engines. Any remaining puzzles have been temporarily deactivated and will be updated in the future. This means that all modes are now updated to version 3, including Puzzle Climb and Puzzle Academy.

These updates significantly improve the quality and the educational value of the puzzles. Some fine-tuning and further improvements of the algorithms are still ongoing, including improvements to defence puzzles and Puzzle Inception.

Examples of improvements

This had previously been a puzzle where you were supposed to win a piece with 1...Bxe4 2.Bxe4 f5 3.Qh3 fxe4, however, new engines show that 3...fxe4? is actually a mistake, allowing White to launch a winning attack with 4.f5!. The puzzle has been removed.

Here the intended solution was the simple 1...Rxc1 2.Kxc1 axb3, however, new engines show that after 3.Kd2!, White is able to build a fortress and draw the game. This puzzle was removed as well.

Previously, the puzzle ended after the simple 1.Nc7 h5 2.Nxb5, but actually after 2...h4 the endgame is still quite complicated, and White has to be very precise. In version 3, this puzzle continues for quite a few more moves. Click the puzzle to try to win this endgame.

A complex example that highlights the strengths of the new algorithm. Click through to the solution view to see many variations analyzed. There is also a video by Daniel King with more explanations.

Puzzle Academy content update

Alongside the algorithm improvements, Puzzle Academy has received a major content update across multiple courses, including new skills, levels, and guides:

Tactics: Garbage Collection, Level 2

In the "Tactics" course, there is now a second level for the "Garbage Collection" skill. These puzzles are about positions where both sides threaten material-winning captures, a situation that can often be confusing and lead to many blunders.

Here is an example from the new level:

White has just played the bishop sacrifice 1.Ba3-e7?, attacking Black's queen, and also discovering an attack from White's rook on Black's rook on the a-file. However, this was a blunder, because Black can capture the bishop with Kxe7!, which also opens the back-rank so that the rook on a8 is now protected by the rook on h8.

Here is a more complicated example:

Black has sacrificed the queen, but can get a new queen by capturing on c1 with the pawn. However, this would lose after 1...bxc1=Q+? 2.Qxa2. Can you find the surprising solution? Click the diagram to solve this puzzle.

Combinations: Clearance for promotion, Level 4

In the "Combinations" course, I've added a new fourth level to the "Clearance for promotion" skill. This includes five-move puzzles where you move a piece out of the way to allow a pawn to promote.

Here are two beautiful examples:

Click the diagram to solve these puzzles.

Checkmate Patterns: Checkmate using a pin, Level 1 - 2

My book "Beginner Chess Puzzles" includes several chapters on checkmate patterns, with examples of checkmate in one move. When selecting puzzles for the book, I was looking for examples that users on ChessPuzzle.net had struggled with. I noticed that many checkmate in one puzzles with a high rating included a pin. I included a section on pins early in the book, and made sure to explain the pins used in the checkmate puzzles.

Later I noticed that even strong players, including grandmasters, spot checkmates that exploit a pin much less quickly than any other checkmate patterns. Therefore it is now time to include this as a new skill in the "Checkmate patterns" course. This update includes the first two levels, with checkmate in one and two moves. Here are some examples:

Countless players have overlooked this famous opening trap, especially in blitz games. 1.Nd6# is a smothered mate, exploiting the pin on the e-file. The knight on d6 cannot be captured by the pawn on e7, because it is pinned by the queen on e2.

Even a player as strong as Fabiano Caruana has overlooked this type of checkmate. Here he missed 1.Qh3# and the game later ended in a draw.

These are two nice examples of checkmate in two moves. Click the diagrams to solve the puzzles.

Checkmate Combinations: Clearance for checkmate attack, Level 1

This is a new skill in the "Checkmate combinations" course. Here the clearance is not to enable a subsequent move, but to ensure that the subsequent move comes with check. This check is either checkmate, or leads to a forced checkmate. Here is a typical example:

Black can win with the knight sacrifice 1...Ng3+!, opening and clearing the h-file, so that 2.hxg3 Qh6# is check and mate.

Defence: Rescue Mission, Level 1

When your opponent threatens to trap one of your pieces, it is time to start a rescue mission. This is a new skill in the "Defence" course. As far as I know, this type of puzzle is not available anywhere else. Here are two examples:

White threatens to trap the bishop with Kb3.
Black has to escape with the bishop: 1...Bb2.

White threatens to trap the queen with Rg1.
Black must create an escape route with 1...e4!

Attacking: Attacking the weakened castling position, Levels 1 - 2

The attacking course now includes two levels about attacking the weakened castling position. When the pawns in front of the king have moved, or have been captured, the king's position is weakened, and it can be vulnerable to attacks. Here is an example from level 2:

Black has weakened the castling position by advancing the g-pawn. Black's bishop is on d6 instead of protecting the dark squares around the king. White can exploit this and force checkmate with the spectacular 1.Qh5!!, for example 1...gxh5 2.Bxh7#.

Endgames: Queen vs Rook, and new guides

The Queen vs Rook skill introduces basic positions for winning with a queen against a rook. This is quite a difficult endgame, but the first level is still fairly easy. It includes positions where you can catch the rook within a few moves, for example:

Click the diagram to try to catch the rook.

Many of the endgame levels now include guides, which explain the key ideas and techniques for these endgames, including king and pawn versus king, and king and queen versus king and pawn.

Experience the Latest Updates and Share Your Thoughts

Try the updated Puzzle Climb to experience the improved puzzles, or explore Puzzle Academy to train your skills step by step. Upgrade to Premium for full access to all new content.

Your feedback is invaluable in making Puzzle Academy the best learning resource for chess enthusiasts. I'd love to hear your thoughts! Feel free to reach out through our contact page.

Happy solving!