You can't draw any conclusions, none at all, from a single attempt. Not even 5-10 attempts. I shook 10 coins in my hand and tossed them on the table. 7 heads, 3 tails. Chance of a heads result? Around 50%.

The sting of failure is absolutely more intense than success. I NQ'd two separate synths at HQ:98% (class quest item) on different days this week. Table flip time. As for the mat synth HQs that came from HQ < 20%? Even at HQ:6%? Not even an in-chair dance.

I have seen that when I macro synth even around 100 base mats, the HQ results are close to the percentages shown. So I'm happy that it seems to be working correctly. When I gather, I have seen a 90% fail 2/5. I've also seen a 35% succeed 4/5. Usually it's ball park accurate. The only pattern is that it seems to be random.