A scale for determining how well one performed in an online game of Halo 3. This scale is based on an individual's kill-death spread plus half of their assisted kills. This scale was created as a superior alternative to the kill-death spread as a mode of determining performance because of the Trey Sweeney Scale's ability to factor in kills the individual assisted in achieving.
Trey Sweeney had 12 kills and 10 deaths, so his kill-death spread is +2. He had 8 assists, which divided in half is 4. So while normally it would be said he did o.k. with a spread of +2, he actually did really well based on the Trey Sweeney Scale, which rates him at +6. Trey is happier with this because he almost killed several people who were then picked off by some n00b farshotting with a BR.