I would like to see engine-engine games with take back

[Uri Blass]

The idea is the following:

one side has to win and the second side need to draw.
Drawing is easier so the side that needs to win is allowed to take back moves.


Rules can be the following:
Every player has at most average of 30 seconds per move(it means it can use less than 30 seconds in part of the moves but always the average time per move should be lower than 30 seconds).

Suppose white needs to win the game(you can also decide that black needs to win the game).
It means that white is also allowed to take back moves in the first 5 hours and try something different.
If white does not win by mate in the first 5 hours the programs continue the game.

If White win it is considered a win for white.
If white does not win it is considered a win for black.

Of course it is possible to change the 30 seconds and 5 hours to different times.
Note that programmers will have to change their program to support the take back option when the program may try risky ideas in order to win because even if the risky idea lose they can try something else.

The question is what is the times that are going to be fair(meaning white wins half of the games) and what are going to be the changes that the programmers make to make their engines better in these conditions.

For opening book I suggest that every programmer can use a book that he choose for the competition.
The target is to find how close are machines to be unbeatable in chess so I do not want to limit the playing strength by not allowing books that can help programs to be unbeatable in chess.