I feel that it is dramatically less like playing blindfold chess and more like playing normal chess. You can always refer to the code or state in the debugger

I feel that it is dramatically less like playing blindfold chess and more like playing normal chess. You can always refer to the code or state in the debugger at a given time, but being able to think through steps ahead in your head is very helpful. Likewise in normal chess you can always refer back to the board to reset your mental state, but it helps to be able to think 5 moves into advance. Playing blindfold chess isn't much harder at the beginning of the game; you can always reset to the initial state and replay moves if you want to. But as the game goes on it becomes hard to remember "Did I move the A rook or the H rook?", basic playing of the game isn't too hard. If you could refer to the board every 10 moves, blindfold would not be very hard at all. When programming, all the information is there, being able to run it in your head is just faster than asking the computer to do it.