[hdhwbruz] Late pawn handicap

Play starts like a normal chess game, but on move (say) 80, a pawn appears on the second rank of the e file for the weaker player.  (Details yet to be worked out of what to do if that square is occupied on that move.)  This provides a very small handicap in favor of the weaker player.  The player has to survive until move 80, then center pawns are the weakest in the endgame, then the pawn has a long distance to go before promotion.

Perhaps like shogi, the extra pawn appears in hand, able to be dropped on KP2 by the player any time after move 80.

Inspired by the 1-stone tengen handicap in go 囲碁.  Opening play concentrates on the corners and sides, so the tengen stone becomes relevant only relatively late in the game.