I dont understand why the best in bags is recommending I try to increase versatility and decrease mastery when my custom stat distribution is set to vers as the lowest priority and mastery is the second highest even with telling it to prioritise secondary stats as the highest?
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This has to do with what items you have available to you. Your priority puts crit and vers as nearly equal in value, with mastery a little bit higher and haste a little higher than that.
The optimizer is trying to put on all your items with haste. Those items happen to also have versatility, and not mastery. The versatility increase is a side effect of trying to increase your haste, since your distribution suggests that maybe it isn’t much of a loss to do so.
Reduce the value of versatility just a little bit more and I think you’ll get a result closer to what you are looking for:
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