Guatemala Defense (2...Ba6)

The idea

With 2...Ba6, Black aims the bishop at f1 instead of e4. The point is to trade it for White's light-squared bishop, the piece that would otherwise defend e4 from d3 and point at Black's kingside.

Plans for White

Develop normally and decide whether to allow the trade. Taking on a6 with Bxa6 leaves Black's knight on a6, out of play for a while. White can also keep the bishop with Be2 or avoid the trade with Nf3 and c4.

Plans for Black

Trade the bishops and use the light squares White can no longer cover. Follow with ...e6, ...Nf6 and ...c5 or ...d5 to fight the center. Black's king gets safer once White's attacking bishop is gone.

Watch out for

For Black, losing time. The bishop on a6 can be traded with a gain of development for White, so Black must catch up quickly with ...e6 and ...Nf6.

For White, the light squares. Once the light-squared bishops are gone, d3, e4 and the kingside light squares are harder to defend.