[BlindEyeHalo]

The issue with these "ghost chess" implementations are always the same things

1. How do captured pieces get removed? 2. How to handle pieces that move through other pieces (knights, castling)? 3. How to promote a pawn?

I have never seen these solved in something that is not awkward and neither seems to be the case here.

[inanutshellus]

1. I see what you mean. Without a dual gantry it'd first move the taken piece off of the board and abandon it, then move the capturing piece. The meantime'd be awkward. Perhaps he could move the piece to the corner of the current square, move the capturing piece in, then move the captured piece off the board. That'd be slow and tedious to watch. So. No great solution, which was your point I think.

2. Personally I thought this implementation demonstrated this pretty reasonably both with castling and with moving the knight. He kinda "cheats" in that his squares are pretty large compared to the pieces, so the jumping piece can just travel /between/ ranks and files. Seems pretty nice to me.