Grinding Trials for power level may be more efficient than solo ops or other methods

Hey y'all. Prime drops are needed to get from power level 400 to 450. There's widespread speculation that the drop rate of prime engrams in activities like solo ops is somewhere around one in twenty--and that if you somehow make it to your twentieth completion without a drop then you're guaranteed one. My own experience in Trials of Osiris nets me one about every eight matches, with one always dropping at ten matches if I haven't seen one for that long. That makes me think that the drop rate is doubled and the drop protection kicks in at half the completions of other portal activities. It would be great if we could add more data to the set, but a snippet of my (very 3v3-average player) experience at 400+ power level (GR9) looks like this.

|Result|Rewards| |:-|:-| |\*Loss|Prime T5| |Win|T4 + Shard| |Win|T4 + Shard + Prism| |Loss|T4| |Loss|T4| |Loss|T4 + Prism| |Win|T4 + Prism| |Win|T4 + Prism| |Win|T4| |Loss|T2| |\*Loss|Prime T5 + T4 + Prism| |Loss|T3| |Loss|T3| |Loss|T2| |Loss|T3| |Win|T4 + Shard| |Loss|T2| |\*Win|Prime T5 + T4 + Shard +| |Loss|T4 + Prism| |Win|T4| |Win|T4 + Prism| |Win|T4 + T4 + 2 Prisms| |Win|T4 + T2 + Shard| |Win|T4| |Win|T4 + T4 + Shard| |Loss|T3| |Win|T4 + Shard| |\*Win|Prime T5 + T4| |Win|T4 + T4 + Prism| |Loss|T2| |Loss|T3| |Win|T4 + Prism| |Win|T4 + T4 + Prism| |Loss|T3| |Loss|T3 + Prism| |\*Win|Prime T5 + T4 + Prism|