Every round is the same three steps. The numbers on this page are the ones the game actually uses; they are read from the same code that runs the board, so they cannot drift from what you play.
A position appears on a full board for a fixed number of seconds. Nothing moves and nothing is hidden. You can end the phase early with Skip, and the clock records how long you actually looked rather than the time you were given.
The board clears. You pick a piece type and color, then tap a square to put a piece down or tap it again to take it back. There is no time limit here, but the clock runs from the moment the board clears until you submit.
Your board is compared square by square with the original. You see which pieces were right, which were wrong, and which you missed, next to the position you were shown, side by side on wide screens and stacked on narrow ones.
Each preset sets two things, how many pieces are on the board and how many seconds you get to look at them. Piece count includes both kings.
| Preset | Pieces | Look time | What it trains |
|---|---|---|---|
| Easy | 2 | 10s | Two kings and nothing else. It teaches the interface and gives you a clean read on whether you can hold two squares under time pressure. |
| Medium | 6 | 10s | Six pieces means both kings plus four more pieces, with the same ten seconds to look as the two-piece preset. |
| Hard | 12 | 8s | Twelve pieces in eight seconds leaves two thirds of a second per piece, so try grouping pieces into shapes rather than remembering them one at a time. |
| Grandmaster | 20 | 5s | Twenty pieces in five seconds is a quarter of a second per piece, so try seeing pawn chains and piece clusters as single units. |
The two sliders move independently of the presets. Piece count runs from 2 to 32 and look time from 2 to 32 seconds. The leaderboard recognizes a round by its piece count, so any count other than the four preset counts makes it a custom game, and custom games stay off the leaderboard.
A piece counts as correct only when everything about it matches the original, the square it stands on, its type, and its color. A knight on the right square in the wrong color is not partial credit, it is wrong.
Accuracy is the share of the original pieces you reproduced exactly, as a percentage, minus ten points for every piece you placed beyond the position's count. It never drops below zero.
Wrong pieces are the original pieces you failed to reproduce, plus any pieces placed beyond the position's count. Placing more pieces than the position held costs you twice, once in the wrong count and once as an accuracy penalty.
The message on the result screen comes straight from your accuracy:
On the leaderboard, entries are ordered by correct pieces first, then by fewest wrong pieces, then by shortest look time, then by shortest solution time. Accuracy outranks speed, and speed only separates players who scored the same.
Positions are generated fresh for each round rather than taken from real games, but they are not random piles of pieces. Every position the game shows satisfies all of these rules:
Pieces beyond the two kings are split as evenly as the count allows, with white taking the odd piece. Types are drawn in the proportions a real set holds, so pawns are the most common piece you will see and queens the rarest.
The generator tries repeatedly until a position clears every rule above. If it cannot, it falls back to the opening setup trimmed to the requested piece count, so a round always starts.