The six games saw three different start positions (SPs) with the players switching colors for the second game in each position. I'm not sure how the SPs were chosen, but here they are in the order they were played:-
- SP579 BQRNKRNB
- SP896 BBRKQRNN
- SP435 BRNNQKRB
Over on Chess960 Jungle, HarryO discussed the first position in Corner bishops stay on the board, so in this post I'll look at the second position, shown below. The most interesting feature of the position must be the two Bishops aimed at the unprotected g- and h-Pawns. Note that the players can castle O-O-O already on the first move.
Aronian had White in the first game and both players started with the same first move, 1.b3. This threatens 2.Bxg7, winning a Pawn and the exchange. White could also have moved the c-Pawn, threatening the h-Pawn. Other reasonable first moves are 1.Ng3 and 1.Nf3, covering White's weak Kingside Pawns and threatening Black's. The move 1.Ng3 could even lead to an unusual Queen swap after 1...Ng6 2.Nf5 Nf4 3.Nxg7 Nxg2 4.Nxe8 Rxe8 5.Nf3 Nxe1 6.Rxe1.
After 1.b3, the game with Nakamura as Black continued 1...f6 2.f4 b6 3.Nf3 c5 4.e3 Ng6 5.Ng3 e5 6.fxe5 Nxe5 7.c4 g6 8.O-O-O O-O-O. The game with Aronian as Black continued 1...Nf6 2.e4 c5 3.e5 Ng4 4.f3 Nh6 5.c4 Ng6 6.Ng3 f6 7.exf6 exf6 8.Qxe8+ Kxe8. After both game continuations, White seems to have the upper hand, although Black went on to win both games.
Besides the responses 1...f6 and 1...Nf6, the move 1...b6 looks to be the only reasonable alternative. The defense 1...e5 runs into 2.f4.
For more commentary from the chess blogosphere, see Nakamura Defeats Aronian 3.5-2.5 in Chess960 Match on TheChessMind.net. A typical debate about the merits of chess960 can be found on Chessgames.com's forum Sinquefield Cup (2014), starting on the page I linked.