I think I can assist (personal Target HQ knowledge). Target has a markdown system that allows them to markdown prices based on sales and inventory at the store level. What this does is, allow them to markdown items at a slower rate if they are selling at the price point they are marked or vice versa, take deeper mark downs on slow selling clearance items that have larger inventory at a particular store.
For BTS (holiday etc.) items, they will take an additional markdown on items until all inventory is gone. MD's usually go from -30, -50, -75, -90 then charity. Often times for BTS, if the item can be absorbed into their normal planogram (set of items on the aisle) they will not clearance it, unless there is just far to much to hold for the planogram.
Hope this helps! And Happy deal Hunting!
P.S. If you have a TGT that is not as busy as others, you will often times find some of the best deals!