In this case, I do know a couple of things: 1) it was while I was working on the anime RPG concept that developed into StoryCode AG, and 2) it used the tri-color d3s from the game Toss Up, purchased on sale at Wal-Mart a while back.
As far as I can tell/remember, each side (attacker and defender) was rated for some ability from 1-10. Those ratings were then compared on this chart to produce a "target" square. My thinking (based on looking at this chart) is that each side would then roll a number of the tri-color d3s (equal to their rating?), and add the pluses and minuses (a la a Fudge-like mechanic) to produce a "final" square on the chart. The color on that square would then interpret the result (extreme miss, standard miss, barely a hit, standard hit, extreme hit?) based on the action.
The only problem I see with this mechanic is that strong characters (high rating = more dice) have a higher chance of "evening out" their results to ±0, while weaker characters (lower rating = fewer dice) have a better chance of rolling greens (good) or reds (bad) over a "wash" roll (±0.) I'm thinking that the idea here was that an unskilled player is a wildcard, and a skilled player is more adept (hitting more "in the middle" of his ability every time.)
I do know one more thing about this chart... I never actually tested this idea. I just put mechanic together because I thought the dice were cool. (No offense to Fudge dice, but... c'mon... they're kind of bland.)