Some confusion on the meaning of "exchange"

From: L C <lightcastle_at_...>
Date: Sat, 4 Jul 2009 18:23:13 -0400

 In reading the new rules, I have to admit I'm a little confused by how "exchange" is used. I want to think it means a round between contestants in an extended contest, but sometimes it seems to mean the score of that contest, or any pair of contestants.

 For instance, the assisting rules say that an assist can only apply to a given exchange, and that exchange can not be reduced below 0 but then the actual example shows the assist reducing the overall score of the contest being reduced by one and the assist not being applied to an exchange (as in a roll between the contestants) at all.

 Given the verbiage around assists, I suspect they are supposed to affect the running total and not be limited to adjusting a single exchange. To be honest, I might be wrong in thinking exchange is usually applied to a single round between opponent, but that certainly seems to be how it is used in "asymmetrical exchanges".