Even though we spent a lot of time debating and playing out various forms of Fischer Random over a long period of time in Budapest when Bobby was living at our family home, I will try to simplify the explanation :)
We just randomly placed pieces on our respective sides simultaneously. The only rule is the Bishops have to be on light and dark squares. Below is an example of that:
Then, after countless games like that, we decided to incorporate the castling element. So we kept the same random rules but made sure that the King had to be between the 2 Rooks.
After playing a bunch more games, we finally decided to make it less confusing for the average players. So the final rule is like this:
- White will place the initial piece on the board.
- Black then place the same piece on the same square on the other side.
- Black will place the next piece on the board.
- White then place the same piece on the same square on the other side.
- White will place the next piece on the board, and we continue to rotate until all pieces are placed.
Just as the previous experiments, the two Bishops have to be on dark and light squares, and the King has to be between the two Rooks.
Back then, we did not have computers to generate the random positions. So we had to manually do it as laid out in step 3. After the computer element was introduced, there was no longer any need to manually do it. But all the other rules we created remained the same in the current form for all players worldwide.
The other thing that Bobby and I agreed on is the random element of chess to take away the home preparation. Therefore, we agreed that the position should only be shown to the players minutes before each game, and not 30-60 minutes or even a full day in advance like some attempted to do. This would defeat the original purpose and take the complete random element out of Fisher Random.
As I mentioned in the past, I probably played more Fischer Random games against Bobby than anyone alive today. We carefully discussed the many pros and cons of each idea, then played countless games to test our ideas. We did not just throw things out without extensive testing.
I truly hope that Fischer Random will become more popular in the future. I am very thankful that FIDE has agreed to create a new rating category for Fischer Random, and that Gunnar Bjornsson and the ECU are in total support of Fischer Random Chess.