BENONI SYSTEMS
and The Modern Benoni Def. (aka. Loose Gambit)

Board Position
A Queen's Pawn Side Defence, the Benoni is a sharp, fighting system where Black's QBPawn threatens White's QP and hopes to draw it forward (or off-centre) to upset White's centre.
The P-Q4..P-QB4 system (shown left) is usually encountered in its Modern Benoni form (move 3b, right), a major Indian Defence variation. The name itself is from a Hebrew word Ben-Oni ("child of my sorrow") used in an 1825 chess book title.
Board Position
Popularised by world champion Mikhail Tal in the 1950s and 1960s. Variations from a typical leading line (below) include the Blumenfeld Counter-Gambit and the Benko Gambit.
Begin or Clear or Groups or see move: 1 d4 Nf6 2 c4 c5
then 3 d5 e6 (to Tal's Method:) 4 Nc3 exd5 5 cxd5 d6 6 e4 g6 7 Nf3 Bg7 8 Be2 0-0 9 0-0 Re1
7 Bd3 Bg7 8 Nge2 0-0 9 0-0 a6