Chess Opening Theory/1. d4/1...d5/2. f4

This dubious attack controls e5 once more, with the f-pawn. The name of the opening is the Mason Attack. Although it is not fully sound, it is playable and White scores quite well after the main line, 2...Nc6 3. Nf3 Nf6 4. e3, and White controls lots of the dark squares. However, this slightly weakens the kingside and creates a permanent hole on e5.

2...Nc6 is the most common move, controlling e5 themselves. However, after 3. Nf3 Nf6 4. e3=, White has good central control and is focused on the critical e5 square.

2...Nf6 is similar to 2...Nc6, but doesn't control e5 unlike 2...Nc6. It is principled and develops a piece which controls the new hole on e4 to try and exploit it.

2...Bf5 is the most accurate move, leading to a slightly better position for Black as it develops the bishop and takes advantage of White's slightly weakened kingside and light squares, looking to exploit the new hole on e4.

Overall, the Mason Attack is a dubious but nonetheless playable attack aggressively looking to control e5 and the dark squares in general.