Agree with the above post. Also, so much depends on what your ideal program is and where you interview and how you rank. If your goal is to be at a top 10 children's hospital you should have a significant "star" that distinguishes you, whether it be a research niche, a QI project goal, a mentor, and/or someone with connections. If your goal is to match period, the world is your oyster and there will more than likely be several spots and opportunities for interviews. If you are at an institution with a fellowship already, that is a big plus as you will likely get an interview there and it will be up to you how you choose to rank it.The big programs will more than likely have internal candidates so if you are coming from a smaller program without its own fellowship, it will be tougher to actually match there (you will likely get interviews). Temper your expectations but don't be afraid to aim big.