A tip after poking around: when you're on the page where you select how many tickets you want you can click on a hidden "By Section" link and pick your section

A tip after poking around: when you're on the page where you select how many tickets you want you can click on a hidden "By Section" link and pick your section instead of having it selected for you. I was able to pick up a couple first row balcony tickets using this method.