One cryptarch rank takes 3000 points to level up. Rare engrams contribute 150 points to that rank. I rarely see legendary, and have never once gotten and exotic engram from vanguard tiger strikes. (I have ~270 hours played, so it's statistically significant for the following math) Avg strike time: ~20 minutes (I haven't looked this up, but I feel like you're close here) Avg number of rare engrams acquired/rewarded from 1 strike: 4 (I usually get 1 or 2 rewarded and 1 or 2 dropped, so we'll go high here to adjust for not factoring in the very rare chance of legendary engram award/drop) Num of rare engrams acquired in an hour of strikes: 12 number of cryptarch points from strikes in 1 hour: 1,800 Num of strikes per hour: 3 Num of strikes to level cryptarch: 5 Ok... so I was gonna refute your claim, but after doing the math... yeah I'd say you're not too far off. I think it's probably closer to 6, but I'd be curious to see some actual data over a collection of say 20-50 strikes.