ChessOnes: Friendly online chess with bots at every level and engine review

01 / Overview

About ChessOnes

02 / The challenge

What ChessOnes needed to solve

The big chess sites serve serious players. ChessOnes had to serve people who play now and then, feel quick and kind, and still get every rule exactly right.

1. 01

   Casual players need an opponent at their own level, so the bots had to cover everything from clumsy to strong.

2. 02

   Challenging a friend to a live, timed game had to be simple.

3. 03

   Every rule had to be right, because one wrong check ruins trust in the whole board.

4. 04

   Players wanted to learn from a lost game without paying a coach.

03 / What we built

How we built ChessOnes

We built a Next.js web app on an Express and MongoDB API, with Stockfish behind every bot, hint and review and Socket.IO carrying live games between friends.

• 01

  Eleven engine bots

  Each bot maps an ELO figure from 800 to 2850 onto Stockfish's skill setting and thinking time. Players pick an opponent that matches them, from clumsy to strong.

• 02

  Rules applied on the server

  The server applies castling, en passant, promotion and threefold repetition, so special moves and draws are handled correctly in every game.

• 03

  Live games with friends

  Socket.IO carries moves, ready signals, draw offers and undo between friends. Each side sees both clocks, captured pieces, the move history and whether the other player is connected.

• 04

  Five ways to play

  The game picker offers Find My Rival, Bot Battles, Challenge a Buddy, Guided Match and Local Multiplayer on one device. Timed games against a bot or a friend come with hints and undo.

• 05

  Undo that keeps the board honest

  Undo replays the game from the start instead of reversing a single move, so the board can never fall out of step with its move history.

• 06

  Engine game review

  A review route analyzes each move at depth 18 and labels it from brilliant to blunder. The review shows accuracy, key moments, opening and endgame analysis and suggestions for the next game.

• 07

  Play Zone, puzzles and friends

  The home screen shows Blitz and Rapid ratings, milestones, a friends list with invites and pending challenges. Puzzles come with hints, a tactics rating, accuracy, average solve time and a leaderboard.

• 08

  Invitations and background jobs

  Players can invite friends who are not yet members, and Nodemailer sends the invitation. A job every twelve hours expires old challenges, and Stockfish also runs in a browser worker as a fallback.

04 / The results

What changed for ChessOnes

ChessOnes gives a casual player everything they expect from a chess site, in one web app.

• Players sign up, pick a bot at the right level and play a timed game with hints and undo.
• Friends can challenge each other live and offer a draw, with moves passed between boards as they are played.
• Every finished game can be reviewed with an engine, move by move, from brilliant to blunder.
• Undo replays the game from the start, so the board never falls out of step with its history.
• Puzzles, ratings and milestones track a player's progress between games.