When will my favorite Corruption effect be available for purchase?

In World of Warcraft Battle for Azeroth, Corruptions are now available for sale from MOTHER. The ones available change twice weekly, and some are objectively better than others. This brings up the question: When will the specific Corruption you want be offered by MOTHER? Or, if the Corruption that was ideal for your class and spec already appeared, and you didn’t have enough Echoes of Ny’alotha at the time, when will it show up again?

The short answer is, we’re too early in the process to know for sure if there is a pattern, or if there is randomness to it. However, there is speculation, based on hotfix data, as discovered by Dorovon from Big Dumb Guild, there is a predictable order.

What is the order of corruption batches?

There are 52 different Corruptions offered. Each batch has 6 or 7 up for sale at a time. That means it would take 8 different rotations to offer them all. At two a week, that is 4 weeks to cycle through everything. Without any further information, you might assume a Corruption would be available once every four weeks. That would indicate the same repeating pattern, and no randomness.

However, the data discovered implies that it is not random, and not a repeating pattern. What Dorovon found in the data is that there are 8 batches related to Corruption. This would seem to tie back to the rotation of the Corruptions on MOTHER. Each batch had a number associated with it, 1 through 8. There was an order associated with the batches. While the first weeks had them in the order of 1 through 8, afterwards the numbers did not continue to rotate through this. The following weeks were Batch 4, then 8, and then 3.

If this data is true, some Corruptions could be available for a second time in less than four weeks, while others will take much longer to show up again.

One player, Shiftmage of Area 52, has been maintaining a spreadsheet using the data. which you can find here.  This is a record of which Corruptions have been available in which batch, and which week they will be available again, based on the data found.

This will be confirmed whether or not it is accurate on June 16, with the server reset on North America realms. If it is, the Corruptions available will be Batch 4, with Expedient rank II. If it resets back to Batch 1, then it will have Expedient rank III, and we can expect it will probably repeat through them all.