Last year their yield was higher than expected and they had to change around some dorms space and re-open the housing draw for students already at Stanford - so that 1720 was not their goal. It seems like they are intentionally adding about 50 spots this year. They accepted about 180 or so fewer students this year vs last year, so it looks like they are trying to make sure they control the numbers better this year (and if necessary will go to the waitlist if they need to)