FYI- I wrote to Wind Crest about sizing the pan to the hob. Just rec'd an email from them saying they recommend that the pan be no larger than one inch-on each side-for best results. For the 9 inch hob, 11 inches is largest recommended.

Nevertheless, our very own, Ms. Fori, is an experienced Wind Crest induction chef and her experience is that it still works well if it's a little over. A 12 inch bottom on a 9 inch hob will be off the hob for 1 and 1/2 inches on each side.