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## Monday 17 July 2017

### Chess Variants - 960 and Really Bad Chess

Fischer chess, or chess 960, is like queen’s chess which is the standard Orthodox game we know, except in 960, the starting position of the pieces in the back rank is random. It can be played live with a standard chess set, or online through Jocly or Lichess.

There are restrictions on the starting arrangements such as that the king must be between the rooks and that one bishop must be on each colour of square. All the restrictions leave 960 legal arrangements out of 8!/(2!2!2!1!1!) or 5040 unique ways to arrange two rooks, two knights, two bishops, one king and one queen. Both players are given the same arrangements using the files or columns on the board not mirrored for each player's perspective chosen at random.

As far as chess variants go, ‘960’ it's pretty close to Queen’s chess in that it is played with the the same number and types of pieces the same 8 by 8 board and that aside from difference in starting Arrangements no other rule changes are imposed.  The restrictions even ensure that castling in either direction is possible.

If chess 960 is chess done with poetic license then Really Bad Chess (RBC) is done with artistic transgression.  In Really Bad Chess, by Zach Gage (http://reallybadchess.com/presskit/ ) and available on Android and Apple, play is done on an 8 by 8 board with one king and a collection of pawns,  knights, bishops, rooks, and queens arranged into ranks per team. That's about all I can say for certain about the starting state of a Really Bad Chess game.

The pieces each player receives are random, really random. The average piece tends to be more powerful than they would be in a game of Queen’s chess.  At the lowest ranks/difficulties, players typically start with three or four queens as well as a front rank comprised mostly of bishops. At those same lower difficulties the opponent AI would have a much less impressive collection of pieces.

That's one big difference between 960 and RBC: the players are each given their own random set.  When playing against humans, both are treated to a random high-powered arsenal. In ranked mode, games are against the AI and the difference in power is determined by the difficulty setting. At rank/difficulty 0 the player starts with a massive material advantage over the computer. At  100, this advantage is reversed. At 50, both players are given equally strong pieces although the pieces are still different for each player and they are still more powerful on average than in Queen’s chess. For example each player could have two queens and roughly six knights.

Every win in ranked play against the AI increases the difference of the next ranked game. Every loss does the opposite. The AI itself gets no smarter which may be to simplify the concept of difficulty, and it keeps the game reasonably fast because AI does not think to Greater depth at high levels.
This is the first variant I've played where I'm not absolute trash and I have the proof:

The AI tends to strongly value putting you in check and will needlessly sacrifice pieces to do so sometimes. This strategy works well and it partially sidesteps the issue of uneven material value. For example, in difficulties less than 50 even trades for pieces are desirable. At difficulties above 50 they are not. But these material advantages are most important in the endgame. I have played several matches above-50 where I have overcome the material disadvantage and then some only to be checkmated in the mid-game. For example, this game, in which I played as white:

There is an undo button that allows you to take back one move against an artificial intelligence. The button only works to a depth of one move, and it can only be done so many times. Undo uses can be recovered or stockpiled by either watching video ads (5 per view), or direct purchase (\$1.40 per 100). 100 undo uses are bundled with the premium version of the game. The premium version settings are well worth the \$4 if you're going to play 10 or more matches. The default color scheme is hideous but you can change it with premium.

One minor complaint is that the term ‘rank’ is used instead of ‘difficulty’. Rank goes up as you win when logically such a number should decrease. Rank 1 typically means ‘the best’, but not here.
A bigger problem is that pawns are always promoted to queens when promoted. This is usually what I want but cases do exist when another piece is better and the extra decision step isn't that cumbersome.

It's a lot of fun to go on a power trip and play matches with a lot more non-pawn pieces than I would otherwise have. It speeds the game up to the point of absurdity where 50% to 70% of pieces are moved to capture another piece.

The undo button and the wide set of possible scenarios in Really Bad Chess has been a fun tool for a casual player like me to practice tactics, however impossible they would be in a real game. I'm a little worried that games like this are teaching me to play chess incorrectly which will make it harder to develop skill in the standard game. However I've never played chess seriously and I'm in my thirties so the opportunity cost doesn’t seem too steep.

Really Bad Chess is really good at making puzzles as well. It has daily and weekly puzzles which are just matches with preset pieces.