Setting up a position

The same window has two uses:

• the position a study starts from: it opens by itself with New study (⌃⌘N), and from the study with Set up position… as long as it has no moves;
• the position to search for: in the search window, Position tab, with Set up….

A game you write by hand starts from the initial position: to start from another position there is the study. For a study from the position you have on the screen, without putting it together, there is New study from here in the menu of the magnifying glass under the board, or in the Board menu.

Putting the board together

• Placing a piece: drag it from the Pieces card onto the square; or a click on the piece and then a click on each square where it goes. A click on a square that already has that piece removes it.
• Moving: drag the piece from one square to another.
• Removing: drag it off the board, or use Erase and a click on the square.
• Clear board, Starting position, and the button to flip the board.

Paste a FEN and ↩ (or Apply) puts a FEN’s position on the board, whole or with only the placement of the pieces and the side to move. What is missing is filled in: all the castling the board allows, no en passant. The move number is not kept: a study counts its moves from 1.

Side to move, castling, en passant

• Side to move — who moves: White or Black.
• Castling — O-O and O-O-O for each side. A castling right can be turned on only if the king and that rook are on their starting squares.
• En passant — offers only the squares possible in the position: a pawn that has just advanced two squares, next to a pawn of the side to move.

For a study

Use this position is off as long as the position is not possible, and the line in red says why: a pawn on the first or last rank, a missing king, more pieces than one side can have, or the side not to move in check. Once confirmed, the position becomes the start of the study, to be saved with the study.

For a search

Here the window has four tabs, which look for different things:

• Exact position — the same pieces on the same squares and nothing else, with the same side to move, castling rights and en passant: the position as the explorer searches it.
• Partial position — only the pieces you place, wherever the others are. Empty square asks for a square to be free; with Exclude, the pieces you place become forbidden on those squares. The side to move can also be Either side.
• Pawn structure — only the pawns.
• Material — how many pieces of each kind, for at least a certain number of moves, with the typical situations ready-made.