The Thornton Trap
In the Thornton Trap, or “the Thornton Castling Trap,” a player castles on the queenside and surrenders check to win an exposed rook. The diagram below shows a typical example.
If 1…Rxb2? White wins the black rook with 2.0-0-0+!
According to chess historian Edward Winter, the earliest example of this trap was at Thornton-Boultbee, 1884.
Lessons from the Thornton Trap
Aside from being a neat tactic with a funny name, trainers should teach the Thornton Trap to students of all levels for a number of reasons. The Thornton Trap:
- teaches newcomers to castling on the queenside and introduces the idea that castling is not just a defensive move.
- is a simultaneous attack. Two chess pieces (a king and a rook) threaten two targets, a vacant rook and a king. This differs from a fork or other double attacks.
- shows a blind spot in chess. Students can discuss why a good tactician might fall into this trap. Maybe it has something to do with the unique moves of castling on the queenside. Maybe it has something to do with the fact that people overlook “sideways movement”. A player may forget that the loose rook on b2 can be threatened. Or maybe players don’t think about castle this late in the game. Talking about blind spots and asking, “Why do people make mistakes?” can help reduce errors and improve tactical awareness.
Maneuver Search for Thornton traps
ChessBase Maneuver Trials can be used to find many chess patterns. To perform a ChessBase maneuver attempt to find Thornton Traps:
1. In the database window, right-click on your reference database (or your largest database). Click Search.
2. In the basic search database window, click Advanced.
3. In the Advanced Search Database window, first click Reset. Helpful Tip: If you ever have trouble with a ChessBase search, click Reset and try again.
4. Click the Location tab. Assemble the board as shown below. In this example, there is intentionally no black king. In the next step we will search for chess so that ChessBase knows where to “place” the black king in the search. Alternatively, you can simply place a black king on d8 or d7, but you will get fewer search results
5. Click on the Maneuvers tab. Click Insert/New. In the piece box, select K for king. In the next field, enter e1. In the next box, type c1. Click the check box. We instruct ChessBase to look for games in which White moves the king from e1 to c1 (castling on the queenside) and tests Black’s king. Click OK and ChessBase will start searching.
6. The search results should look something like this, but may differ depending on the database used.
7. Click on any game in the search results list. Press Ctrl + A to select all games. Right click on the highlighted games –> Output -> Database. Name the file “Thornton Traps” or you can select an existing file and ChessBase will add the games to the file.
Finally, you can load your Thornton Traps file and delete any games that you don’t want to show your students. Comment, print or share the ones you like the most. You can even create a worksheet where the solution to each puzzle is 0-0-0+!.