Why 84%?

Yin Fire is 丁, a candle; Yin Wood is 乙, a climbing vine. Wood feeds Fire in the generating cycle. Generating pairs start at 86. Both are yin, which takes away 2: 86 − 2 = 84.

Out of the 10 stems, 3 would score higher with Yin Fire.

Only the year's stem is used — this is a quick game, not a saju (Four Pillars) reading. The points are our own design; the five-element cycles are a tradition, not a science.