The Knicks' explanation for announcing a sellout of 19,763:
The spokesperson, who didn't want to be quoted, said nearly all of the tickets for the season were sold before the first game. But about 150 tickets for any given contest become available on game day or shortly before, when home and visiting players, and team and Garden officials, return tickets.
If those tickets are given back before game day, they are distributed through a Garden charity. Otherwise, the tickets go on sale game day.
Those tickets, if unsold, are bought back by the team to declare a sellout. The seats are supposedly given to team or Garden employees.