So...took me a moment to understand the Priority Window concept, but I wonder if the idea is you will be put into one of the 4 windows for the rest of the time (until full capacity allowed), and for each game they will switch around the order, to make it fair?
I think every match has a new ballot for which priority group STHs will be put into. From what Barber has said previously being selected in the ballot for 1 game doesn't change anything for the next game. It's a fresh ballot each time.
Also assuming the point of having priority windows and needing to actually claim your ticket, is to stop people being allocated tickets who then just don't bother turning up/don't even notice they've been "selected"? As it would cause a massive binfest if 2,000 were selected but 50-100 didn't bother turning up, when other fans would've gladly taken their spot.
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Having to log in and actually select tickets if you've been picked in the ballot is a much better idea than being assigned a ticket automatically. Means if you don't want go then just don't select your ticket and let it be offered to others who do want to go.