The way I was thinking is there would probably be some semblance of a number involved in calculating the trade - so say -100 if swung towards player A. 0 if perfectly balanced. +100 if swung towards player B. All numbers in between indicating the degree of balance and to which side.
If that number was stored as part of the trade details, then it could be rendered accordingly. How it would be displayed in the forum, eh, pass. In terms of the league trades page, well the page is obv html. It would be a case of rendering a display.