Need help understanding BiS(best in slot)

[Docent]

If item1 is worth 400 points and item2 is worth 430 points, item2 is the clear BiS.

Everything is situational. We used to hate having to repeat that over and over and FFXI, but it's still true here.

Sometimes the choices are obvious..
Let's say:
A) hypothetical ilevel 130 body with Crit (Major) + Det (Minor)
B) hypothetical ilevel 130 body with Det (Major) + Skill Speed (Minor)

Most of the classes will end up with a "higher score" for Item (A), and will build their best in slot around that item

But if the options are:
A) hypothetical ilevel 130 body with Accuracy (Major) + Crit (Minor)
B) hypothetical ilevel 130 body with Crit (Major) + Skill speed (Minor)

You may end up with piece (A) as the best in slot, because that's the best place to get Accuracy to the amount you need, given the rest of the gear that exist / that you own.
It doesn't even take stats weight, however, to understand that item (B) will outperform item (A) in any situations where you don't need that accuracy.

"Best in slot" is nice and all, but you need to specify what it's going to be used for.

[Zaft]

snip

Of course. BiS is always going to differ based on the content it is applied too. But what Makado stated is plain wrong. Each class has its own weights, each class has its own requirements. WAR needs to ACC cap, and then hit the SS breakpoint for 9-hit Berserk, and then get Det and Crit, for example. If you just throw on gear without knowing what you need, you're going to come out subpar.

Edit: For example, I see this thrown around as "WAR BIS" a lot by people who don't understand priorities. See the glaring problem? http://ffxiv.ariyala.com/PQXT

[Docent]

Edit: For example, I see this thrown around as "WAR BIS" a lot by people who don't understand priorities. See the glaring problem? http://ffxiv.ariyala.com/PQXT

Where to start?

Under accuracy cap for T13 (555/558), over accuracy cap for anything else in the game, and doesn't have the "minimum" of 390 skill speed recommended by DPS-focused warriors?
571 accuracy if the eat Caviar, which seems overkill. (Is that BiS supposed to eat Black Truffles, or god forbid, bacon bread?)
It's not using melded Platinum accessories, either...