What symbols would each character symbolize in a game of chess?

An
"" in chess is when only two kings are left on the board. Neither can win or lose. All
that happen is that they can endlessly move around, and around, and around, never putting each
other into check, and the game only ending when it is aborted as a stalemate.

In that sense, Hamm and Clov are both kings, unable to finish anything (note the first
and last lines of the play!) moving around the chess board.

But, it's
important to say that the characters share characteristics which are perhaps supposed to suggest
other chess pieces. Hamm (who sometimes openly utters "Me to play") is most like the
King, a very weak and vulnerable, but also a very powerful piece: to defeat the king is to win
the game.  Like a chess king, his movement is restricted, and he relies on another piece to
protect him (Clov!)

Clov's odd movement patterns and his staggering walk seem
closest to the odd "L" movement-turns of a Knight. Nagg and Nell are weak, and
unimportant pawns, the loss of whom is insignificant. Nell's death bothers no one.

But the key chess point is that, ironically, the "Endgame" means the game can
never end, but must continue and continue and continue.