ZenChess (my variant, impossible 4 comp)

Here is the long awaited ZenChess. It uses only standard pieces and board, and everything you know and love about chess stays true to chess.

The rules are as follows: 

As always, white moves first.

The game begins with an EMPTY board. The players alternate placing pieces and pawns on the board, starting with the kings.  On the first move, each player MUST place his king on a square of their back rank. The 9 squares surrounding his king are his safe squares (squares your opponent may not place a piece). For example, if the king is on d1, his nine squares are d1-3,c1-3,e1-3. If he is on a1, its a1-3,b1-3,c1-3. You may NOT place your opponent in check.

Move 2 will ALWAYS be a pawn move, and move 3 will ALWAYS be a piece move (you get the idea). Pawns may only be placed (3) squares away from the queening rank (so 5th for white, 4th for black). Pawns are LIMITED to ONE per file, however, you may place two pawns on a file if you do not have the ability to place it on its own file* (this may happen, sometimes all squares are taken on a file).

You  may only have 1 bishop of each color. There is no castling. En Passant exists.

After the placing of the pieces is completed, a game of chess commences! (White moves first)

I have played many games of ZenChess and have found it very balanced. I look forward to hearing what you guys think.

Why do you think this is impossible (or even difficult) for a computer?

It is because of the amount of available moves that a computer would have to consider (think about it, you have an entire selection of pieces and pawns that can be placed nearly anywhere on the board, the number of possible occurances dwarfs chess). In this respect it is similar to GO, only each piece in GO is exactly the same, whereas in ZenChess they are chess pieces with different powers, making the computers job tough indeed.

In Shogi you can also place pieces you have in hand anywhere on the board. Yet computers play Shogi. The problem with Go is not the large number of moves, but that there is no simple way to statically evaluate positions. For Chess it is pretty well known what makes a position good or bad, and the computer could simply place its pieces according to those rules.

Note that making a game hard does not necessarily disadvantage the computer. It also gets more difficult for the human player. Computers are much better than humans in processing huge numbers of positions.

I understand that. Computers can't play the opening very well, due to the high number of possibilities, and having the empty board makes it unfathomably more complex than the opening stages of a chess game.

Also, in shogi, the game starts with a static position, and you rarely get more than a few pieces to hold on to. Imagine having all of the pawns and pieces to place.

The number of moves in the opening is actually much lower than in the middle-game, in Chess. You start with only 20 moves; the average is more like 40.

In Shogi the game starts in a static position, but that is of course not where you have pieces in hand or where the game is decided. Also not that for the number of moves it does not matter if you have just one Rook in hand or two. Dropping one or the other is the same. It is just that you can keep it up longer. It is the number of piece types in hand that determines the number of moves. In Chess there are only 5 piece types (after you dropped the King). It occurs very often in Shogi that you have 4 or 5 piece types in hand; there are 7 unpromoted types there. And Shogi players try to keep always a Pawn in hand, so in the course of a trade you easily accumulate 3 more pieces. And the board is larger, so there are more squares to drop on, so with 4 piece types in hand you already have more possible drop moves than in Chess with 5.

I don't thinkyour variant would be very difficult for a computer at all. The computer would be much better to judge the latent tactics you are building up when dropping the pieces than any human. If there is anything computers are unbeatable in, it is in tactics.