A three digit IBA number is one of the most coveted possessions in our little world (along with the IBR plate backer that comes with it). The finishers of the last IBR (who didn't already have a 3 digit number) received 5xx series IBA numbers, meaning (to me at least) that half of the potential 3 digit numbers are gone. Ive always wondered, what will the 1000th new IBR finisher's number be? Are 4 digit numbers reserved as well?