The best chance of acceptance seemed to be EA/ED2 , but that was last year. If he has two top choices then I would go that route, EA to Yale or Princeton or Pomona…then ED2 to UChicago. My daughter chose that route even though UChicago was her first choice (wanting to maximize her chances at two schools, and that she would be perfectly happy at either). If UChicago is the first choice by a good margin then I advise ED1.