Amy Cappellazzo, who regularly appeared on this list as Christie’s chairman of postwar and contemporary development, left the auction house this year to team up with adviser sans pareil, Allan Schwartzman. His is the curatorial vision that transformed Bernardo Paz’s Inhotim from Fitzcarraldo fantasy to major institution and guided Howard Rachofsky in building his collection of postwar Italian and Japanese art, now promised to the Dallas Museum of Art. Called the most creditable person in the artworld by a colleague – he works on retainer rather than the standard 10-percent commission – his client roster also includes Nicolas Berggruen and Penny Pritzker, among others. Cappellazzo brings her own Rolodex to Schwartzman’s already extraordinary level of access. Their joint venture, Art Agency, Partners, aims, in her words, to build an empire, by developing a new business model combining curatorial and financial expertise.