"4) Handicaps:   [ ... ]
           If the players have agreed to use area counting to score
     the game (Rule 12), White receives an additional point of
     compensation for each Black handicap stone after the first."

               [ ... ]

           "12) Counting.  There are two methods for counting the
     score at the end of the game.  One is based on terriroty, the
     other on area.  Although players' scores may differ under the
     two methods, the difference in their scores, and the game
     result, will be the same."

                 ( AGA Concise Rules of Go, April 1, 1991 )
    http://www.usgo.org/resources/downloads/conciserules.pdf

          One might think there seems to be a contradiction.  The AGA
     Rules state that game result will be the same under either method,
     and yet you report someone's insistence upon selecting an
     optional rule which would threaten to alter the game result.  This
     may be resolved by the characterization of player agreement.
     If players have not agreed to compensate White for Black's
     handicap stones by means of Area Counting then agreements
     cannot be in effect.  They must revert to Territory Counting.

          The "complete rules" states a similar procedure:
   http://www.usgo.org/resources/downloads/completerules.pdf

          Here is an argument that payback for handicap stones
     makes no difference:
     http://www-2.cs.cmu.edu/~wjh/go/rules/AGA.commentary.html

------------------------------ begin insert --------

     "Finally, in a handicap game, the additional points of compensation
     paid by Black to White can be thought of as "reverse pass stones"
     ensuring that both players have, in effect, still played exactly the
     same number of stones.

     If we assume that the two players have played the same number
     of stones, with no neutral points left on the board, and that the
     score in equation [1] is equal to k, we have:

           (Ab + Tb) - (Aw + Tw) = k
           But

            (Ab + Tb) + (Aw + Tw) = 361 [2]
           So k must be odd!

     This implies that if such a game is even on the board by
     traditional territorial counting (without pass stones), Black must
     have made the last move! At one time, the Chinese rules compensated
     White with an extra point when Black got the last move. If Black's
     last move was to fill a ko he or she had won, however, it was
     deemed unfair to penalize him or her, so eventually the Chinese
     removed this proviso. Requiring that White always have the last move
     and using pass stones removes the possibility of a "pass fight" over
     who gets the very last move.

     If there are neutral points on the board at the end of the game
     (presumably in seki, since the players would naturally fill all
     dame under the area system), the same argument still shows that
     the two systems give the same result if the players have played the
     same number of stones, but the parity of k will depend on the number
     of neutral points; if there are an odd number of neutral points, k
     will be even, and vice versa. This may explain why some rule
     systems go to great lengths to award all points in seki.

     Finally, note that in the confirmation phase, by our rules, the
     final result remains the same (that is, the "same" as would be
     calculated before playing out the confirmation phase if the status
     of all groups were taken to be whatever it proves to be through
     the confirmation process!) Since the game is over, we can assume
     that all empty points belong to the territory of one or the other
     of the players. Under area counting, stones of either color played
     into one's own territory or into the opponent's territory will not
     change the score--nor will the "pass" stones. Under territorial
     counting, every stone played into one's own or the opponent's
     territory will cost a point--but by requiring that the players make
     the same number of moves, and by insuring that even passes
     cost a point (the "pass" stones), we insure that the end result
     is still the same.

             [ ... ]

     Scoring the Game: The rules allows the use of either "area" or
     "territory" counting, by prior agreement. The use of pass stones
     and the requirement that the two players each make the same
     number of moves insures that the two methods will give the same
     result in all even games. The requirement that Black compensate
     White for any handicap stones given insures the same result in
     handicap games as well. (This could equally well have been
     achieved by treating White's first n-1 moves in an n-stone handicap
     game as passes, requiring White to pass Black n-1 pass stones.
     The results would then be the same, but the value of a handicap
     stone would then change from what we are used to; New Zealand
     effectively uses this system (they only count by area), but most
     other Chinese-style (area counting) rules seem to compensate
     White as we do.)

-------------------------------- end insert --------

     This last paragraph in the "rules explanation" incorrectly suggests
     that prior agreement is necessary for the choice of either method
     of counting.  Clearly the AGA Rules stipulate that prior agreement
     is necessary only when asking for Area Counting.

                      - regards
                      - jb