Snapshot id: 8a5d48de53f3472b993ea2ef5328a13a
Sims show that the ilvl 460 item is superior to the ilvl 420 item, even when using the ilvl 460 item drops corruption below 25 corruption (and thus HoD no longer triggers).
https://www.askmrrobot.com/wow/simulator/report/05d5b955bb4a40dc9fdb240a462a766c
Yet, preserved contaminant upgrade finder doesn’t recommend corrupting the ilvl 460 item, and best in bags suggests continuing to use the ilvl 420 item with corruption.
Indeed, pinning the ilvl 460 item and reoptimizing (leading to another corrupted item being pulled in for feet to keep corruption above 25) shows “+0.20% HPS”, even without a full sim. So why isn’t it being found by BiB?
All of these solutions are extremely close together. The optimizer cannot always find the top scoring set of gear - but it always gets very close. Within 0.2% is well within any reasonable margin of error when we’re talking about trillions of potential gear combos. There is no way you could feel any difference between keeping the BiB solution vs the solution with the 460 leggings on, from a healing output perspective.
It would be great if there wasn’t any margin of error at all, but it is a necessity with how many ways gear can be combined.
Totally understood. It’s definitely a rounding error, and now that I know there’s such a little difference (but a small improvement), I can equip the 460 item in order to look better on the lfg ilvl display, heh.
I hate the game design where it encourages people to do ridiculous sidegrades or downgrades to have a higher chance of being invited to play 
The lfg shows people the item level in your bag, not equipped, just FYI.
… oh, TIL! thank you so much!