Whereas checkers has a mere 500-billion-billion positions (5 followed by 20 zeroes), chess is though to have about a billion-trillion-trillion-trillion positions (1 followed by 45 zeroes).
"Given the effort required to solve checkers," Schaeffer reports, "chess will remain unsolved for a long time, barring the invention of new technology."
Well, I'm glad to hear that. Even so, I have always had an interest in chess variants since I first learned the game, going all the way back to the 1970's when I purchased the fascinating Dover Publications (they have a lot of great classic chess books available) volume "Guide to Fairy Chess" by Anthony Stewart Mackay Dickins.
Here, summarized from Chess-Poster.com are some of the more common suggestions for "improving" the game of chess:
- Modify (or abolish) the castling rules.
- Add new chess pieces that combine the movements of several pieces i.e. a piece that combines the moves of a rook and knight or a bishop and knight - or even a queen and knight.
- Change the initial starting positions of the chess pieces. This is one of the more popular proposals as found in Chess960 (also known as Fischer Random Chess).
- Changing the way pawns move (the ability to move three squares forward on the first move or to move one or two squares forward each turn) or the ways pawns can be promoted (promotion of pawns to minor pieces on reaching the seventh rank).
- Changing the size or layout of the chessboard (very often to accommodate the extra chess pieces as mentioned in the 2nd bullet).