I guess you could call it that, but technically it is cumulative probability theory. In a Bernoulli trial you either pass or fail as the outcome. A sequence of such events has an ever-increasing chance of success, even though each individual trial has the same fixed probability. An example for 43% chance on a single attempt is given below for multiple attempts.
| nTries | Cumulative Chance |
|---|---|
| 1 | 43% |
| 2 | 67.5% |
| 3 | 81.5% |
| 4 | 89.4% |
| 5 | 94.0% |
| 6 | 96.6% |
| 7 | 98.0% |
| 8 | 98.9% |
| 9 | 99.4% |
| 10 | 99.6% |
No, my engineer can do it, but leveling Engineering has been more difficult for me than leveling Blacksmithing, so she can’t make a 405 gun yet. Your specific experience is likely to do with whether your realm is high population or low population. It might just be that there are few engineers that can make the gun on your realm, or the engineers that can, don’t check public orders (since it’s so broken, many crafters have given up on ever seeing one).
Hopefully Blizzard does something with Personal Orders so you don’t have spam/watch Trade Chat to find a match between a crafter and a buyer. Public Orders seem to work fine according Blizzard’s statements, so while it could also use a tweak, I’m not expecting any changes to Public Orders.