The FIDE Grand Prix was a series of four tournaments, featuring 16 elite players battling for two berths in the 2016 Candidates Tournament, which will determine a challenger to face Magnus Carlsen in a World Championship Match later that year.
Each of the four Grand Prix events was a 12 player Round Robin (so each player sits out one of the three events.) Points were awarded based on order of finish, and the goal was to score the most total points over the course of the three events played. The top finishers in the Grand Prix were:
1. Fabiano Caruana
2. Hikaru Nakamura
3. Dmitry Jakovenko
4. Evgeny Tomashevsky
As a result, Caruana and Nakamura have definitively earned places in the 2016 Candidates Tournament.
If either Caruana or Nakamura manages to finish in the top two of the World Cup in September, 2015, which is a higher precedence qualifier, then Jakovenko would qualify instead, as spots go to the top two Grand Prix finishers who did not already qualify via the World Cup. Otherwise, Jakovenko will be the first alternate should any of the original eight Candidates not participate in the tournament for any reason.