This variant of Chess is aimed at directly addressing the main problem I perceive in Chess play at the present day: defensive play on both sides being the rational strategy, but leading to an excessive number of drawn games.
It would be used with the following simplified form of Dynamic Scoring:
Checkmate: 100 points for the player forcing checkmate, 0 points for the checkmated player.
Stalemate: 60 points for the player forcing stalemate, 40 points for the stalemated player.
Perpetual check: If Black gives perpetual check, he obtains 55 points, and White obtains 45 points; if White gives perpetual check, he obtains 51 points, and Black obtains 49 points.
In a match, the first few games might be played normally except for the use of Dynamic Scoring as above; and then, if the match is tied, the remaining games would be played according to Tiebraker Chess, the variant I am about to describe.
Tiebraker Chess requires one additional piece of equipment: either a disk for each player of that player's color, or a single disk which is white on one side and black on the other. The latter could be borrowed from a Reversi set.
The play and rules are identical to normal Chess, but with the version of Dynamic Scoring as described above, except for the following:
A player may, on his turn, instead of moving, replace his King with a disk of the same color.
Once this is done, on all subsequent moves:
The player who has done this may not move his King.
If a player who is not in check has a capturing move open to him, that player must either make a capture or give check.
The purpose of this rule is to make it possible, when a player has the advantage, but cannot avoid a draw because of excessively defensive play, to have the opportunity to open up his opponent's position through sacrificial play.
In this case, the player who has replaced his King will recieve 90 points, with his opponent receiving 10 points, if he checkmates his opponent. Stalemate remains a 60-40 split for both players. Perpetual check by the player who has replaced his King is a draw, with a 50-50 split of points.
However, on the next move, the opponent may reject this choice of changing the rules of the game. There are two options for doing so.
The other player returns the first player's King to the board, and replaces his own King with a disk.
Now, he becomes the player who may not move his King, while the first player can once again move his King normally for the remainder of the game.
For the next ten moves on the part of both players, the game is played and scored normally, as if nothing had happened, except for the other player being unable to move his King.
After those ten moves, capture becomes compulsory as above, as if the first player's move had not been rejected. Both players recieve a 90-10 split for checkmate, and a 60-40 split for stalemate, but perpetual check is a draw.
The purpose of this rule is to ensure that the move of immobilizing one's King is not used to escape from zugzwang.
The other player returns the first player's King to the board, without replacing his own King with a disk.
In this case, play proceeds normally, with both players able to move their Kings, and with capture being strictly optional, until the end of the game.
If the other player inflicts checkmate, the points are split 80-20 in his favor; if he inflicts stalemate, the points are split 60-40 in his favor.
For all other cases, including all draws, the first player receives 100 points and the other player 0 points.
This additional option is provided in case the first player is in zugzwang, but the position is of such a nature that exploiting the zugzwang depends on either or both of the other player being able to move his King, and having more than ten moves at his disposal.