Which is better? (Broadway question)?

If there's a specific show you want to see, particularly a "hot" show, you should definitely purchase tickets in advance. If you're more flexible and willing to see whatever there are tickets available for, going to TKTS or going from box office to box office, is a reasonable option.

If you purchase tickets in advance and the show should close before the date of your tickets, you are entitled to a refund.

My question would be, what's the policy if the show to which you have tickets should close before you get there?