Free polyglot chess opening book loaded with traps. 3.8 MB · 248,028 positions · 189 trap lines · both colors.
Your engine plays normal, respectable chess… until the opponent gets greedy. Then the book bites.
189 hand-built trap lines sitting on a full sound repertoire:
- Mate in the opening — Scholar's, Fool's, Legal's Mate, Opera trap
- The famous gambit traps — Stafford, Fried Liver, Evans, Möller, Cochrane
- Two Knights chaos — Traxler (both), Fritz, Ulvestad, Lolli, Nakhmanson, Blackburne Shilling
- Ruy Lopez crimes — Noah's Ark (traps the bishop!), Fishing Pole, Mortimer ideas, Schliemann, Tarrasch trap
- Sicilian punishments — Siberian, Smith-Morra, Scotch, Göring, Grand Prix, Najdorf poison, Sämisch, Sozin, Rossolimo
- Queen's Gambit traps — Elephant, Rubinstein, Cambridge Springs, Winawer Countergambit
- French crimes — Milner-Barry, Winawer-style punishes, Tarrasch Nd2 ideas
- King's Gambit mayhem — Fischer Defense, Cunningham, Falkbeer, Allgaier, Muzio
- Offbeat & fun — Budapest (Kieninger!), Englund, Danish, From's, Orangutan, Grob, Borg, Owen, Halloween, Monkey's Bum, Amar
Underneath: a full sound repertoire base. Trap moves are weighted to dominate, sound theory fills the rest.
Engine vs human — not engine vs engine. In our own testing the book scored about even vs Stockfish without book (trap gambits get refuted by perfect calculation), while winning nearly every game vs human-like opponents. Dubious gambits get refuted by perfect calculation, but humans grab the bait every time. If you want a tournament book for engine-vs-engine, this isn't it. If you want to farm humans, welcome home.
DroidFish (Android): copy trapbook.bin to the DroidFish/book folder → menu → Select opening book. Done.
Arena / Banksia / CuteChess / Scid vs. PC / Lucas Chess: point the opening book path at the .bin. Done.
Komodo, Rodent, Chess System Tal: set the Book File option to the .bin. Done.
Stockfish: no native book support — use the PolyGlot adapter (plays book moves on the engine's behalf) or let your GUI apply the book.
Not for ChessBase/Fritz (proprietary .ctg only).
Scholar's Mate, served straight from the book:
1. e4 e5 2. Qh5 Nc6 3. Bc4 Nf6?? 4. Qxf7#
Stafford Gambit — Black "hangs" the queen, then mates:
1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nc6 4. Nxc6 dxc6 5. d3 Bc5
6. Bg5 Nxe4 7. Bxd8 Bxf2+ 8. Ke2 Bg4#
Will this make my engine stronger? No. A book steers the opening; it doesn't add Elo vs equal opposition. It makes your engine more dangerous vs humans.
Why didn't the trap fire in my game? Traps need the victim to cooperate (greedy/wrong moves). Against correct play the engine just plays sound theory from the same book. That's by design — see "Who is this for" above.
What format is this?
Standard polyglot .bin (sorted, binary-search safe). Anything that reads polyglot books can use it.
MIT — do whatever you want with it. See LICENSE.