How does Best in Slot work?

Hey. Freshly joined human here.
I can’t seem to understand how does Best In Slot optimizer work?
I’m a combat rogue and I have Vindicator’s Brand (81.2dps, 2.6 speed, 19 hit, 38 ap) as a Main Hand weapon. BiS optimizer suggests that aside from changing other items, I should replace my MH to Phosphorescent Blade (71.7dps, 2.4 speed, 11 crit, 40ap), which is 1.82% dps LOSS according to that same optimizer. Why doesn’t it suggest some top notch sword like Spiteblade for example (which is almost 4% more dps only by itself)

Am i missing something here? Even if I lock all my current gear except the MH, optimizer still suggests me to lose dps =\

Snapshot ID is e573c2c6b0604f8c8ea07d3dd8f4b884

Same weird stuff with Best In Bags optimizer. It suggests that I should swap my MH and OH weapons for 9.34% dps LOSS.
Literally, WHAT? O_O

Snapshot ID is 95683b159a094c04b9113d78e92b4561

I’m not sure why the weapons being picked are so strange - we’ll take a look at it. We’ve been having some issues with the weapons that we are trying to work out.

Thank you for the reply. I see that you made some updates, which is a good thing, but:
Best in Slot still shows incorrect weapon upgrade (same as in my 1st post)
Snapshot ID - 2a9e6b05106648e4815219ac6443db0d

Best in Bags shows that The Bladefist fist is an upgrade, which is 100% FALSE if there is no talents changes for the fist specialization.
Snapshot ID - e2d42a7c9d3448ca94ccfa186309a18b

Upgrade finder suggests that Blackout Truncheon (69.7 dps, 1.5 speed, red+yellow socket and chance on hit to increase haste) is an upgrade over Latro’s Shifting Sword (71.8 dps, 1.4 speed, 26 ap, 14 expertise), which can not be true due to how combat rogues work.

Sword specialization + combat potency values fast OH sword most, since it increases the energy generation.
So according to the popular rogue spreadsheets, equipping that mace nets 40-50 dps loss compared to Latro’s Shifting Sword.

Snapshot ID - 12a171dd9d024c6dad809934b6108f10

That and the suggestion to wear Bladefist instead of Vindicator’s Brand makes me think that may be something wrong in how talents are accounted in calculations.

We’re still working on these weapons - we put in a partial fix but not everything is fixed yet. The estimate we were using for the Bladefist was wrong, so I’ve updated that and it will go in the next site update.

Still trying to figure out why the higher scoring weapons aren’t always being picked. The scoring function seems to be working correctly (i.e. the expected weapons get a higher score), but we’re running into some cases where the best scoring items aren’t being picked.