Playing to lose - a chess variant for players with large Elo differences

Here's an idea to provide challenging gameplay for a strong player paired with a weaker opponent - have the win condition become that the stronger player must win with black AFTER some predetermined number of turns.

So, as a specific example, the stronger player plays black and any wins or stalemates by either side before the 25th turn are considered a win for white, whereas if black wins after 26+ turns, then the win goes to black.

To make it even more challenging and to avoid very long games, there could be an upper limit to the number of turns for black to win, so for the example above, it could be that black will also lose on turn 31, if the game hasn't ended.

Just some more ideas to explore at your leisure.  Happy gaming! 

I can imagine scenarios where the white player might even try to chase the black queen around the board and taunt "Come on queenie, get me already"! and other scenarios where black pieces might have to "flee" from a white assault!!   In those cases, black would need to keep enough of a balance to still turn the game around later and win later.