Chess: Knight Fever
Chess with its own engine, Chess960 and an endless Möbius board.
A from-scratch negamax engine with alpha-beta pruning and quiescence search. Play on one device, or across the room over encrypted Wi-Fi with live spectating.
What runs on your device
- Custom negamax engine
- On-device coaching
- MultipeerConnectivity + CryptoKit
About Chess: Knight Fever
Chess: Knight Fever is chess with the volume turned up: full rules, a serious engine and no stuffiness. Play a friend on the couch, a friendly bot, a deep-searching boss engine, or someone on your Wi-Fi.
It also plays Endless: chess on a Möbius strip, where the board wraps with a half-twist, with a 3D view and move-by-move replay. Completely free, with no ads, no subscriptions and everything unlocked.
What you can do
- Pass-and-play, Warm-Up Bot, Boss Fight and Bot Brawl
- Wi-Fi games by QR or four-letter code, with Party Rooms for up to 8 devices
- Endless Möbius chess, playable over Wi-Fi too
- Bullet, Blitz, Rapid and Long time controls with real increments
- The Dojo: 35 guided lessons and engine-verified mate-in-one puzzles
- Unfinished games follow you between iPhone, iPad and Mac through iCloud
How it’s built
- A from-scratch negamax engine with alpha-beta pruning and quiescence search
- A coaching chain of MLX, then Apple Foundation Models, then a deterministic fallback; the model explains moves but never picks them
- Host-authoritative netcode over MultipeerConnectivity, with no server
- Wi-Fi matches run inside MultipeerConnectivity’s encrypted session; player identities are sealed with ChaCha20-Poly1305 before discovery, and saved chat is encrypted on the device
- A WCAG 2.1 AA accessibility pass
A closer look
Behind the build
What if a chessboard had no edges?
Endless mode puts chess on a Möbius strip. How the engine keeps check and checkmate correct across the twist.