On a Railroad between Triangle and Kill Box Mate

Overview

The Triangle mate, also known as the Fish Tail Mate, is now available as a puzzle theme on lichess.org. This post documents background information on it and also describes related patterns, such as, a Railroad and how it connects the Kill Box mate with the Triangle mate. All 3 being available for you to train your calculations skills using our themed puzzles.

The Triangle Mate

The triangle checkmate pattern is a relatively modern addition to recognized chess mating patterns. It essentially incorporates a queen and rook surrounding the opposing king in an area of 2x3 squares, creating a triangular formation that leads to checkmate. The king's ability to move away from the opponents king and queen is often limited by the border of the board or some other constraining factor, such as, an opponents pawn or rook, defending an otherwise available escape route.

This geometric representation showcases the collaboration of these two powerful pieces while emphasizing positional control over the board.

The Railroad

The railroad pattern is a tactical motif seen in middle-game or endgame scenarios, characterized by the positioning of a rook and queen working in tandem to control key squares and trap the opposing king. This pattern is effective for delivering checkmate, particularly when the opponent’s king is restricted along the edges of the board or by other pieces that restrict its ability to move. A Railroad occurs when queen and king form a kill box and a triangle in subsequent moves.

Refer to the sequence of images below and the sample puzzle QeOu4 for a clear understanding of this sequence.

It is interesting to note that I saw most of the railroad patterns in the Triangle theme, while the Kill Box mate theme also contains railroads, but they are much rarer there and often just 3-4 move long.

For me, puzzle themes are just easier to remember and apply, if I can sort and structure them by there relationship in my mind. So, what I would like you to remember is the relationship of a Railroad between the Triangle mate and the Kill Box mate, when you come across coordinating your rook and queen against the opponents king.

There are other mating themes that are similar in the way they work. For example, the Boden's mate (two Bishops) and the Balestra mate (Bishop and Queen) have a similar structure, but these similarities between related themes might be a topic for another blog post in the future.

References

• 36 Checkmate Patterns That All Chess Players Should Know
• The Complete Checkmate Patterns List (with examples)
• Parsing Chess Data to Discover Mating Patterns