1						2
	black is threatening to capture white's Queen					from # 1 - black moves the Rook so that if black captures
	note that black is also concerned about white's
	pawn on e4 - and it's threat of pushing to e5
	(with a fork) and white's dominance of the
	a1-h8 diagonal
	Q) what is black's most active defence					the Queen, then white captures black's Queen
3						4
5						6
							and after 27 …Rxe4 black has gained material (pawn)
							as well as reduced white's dominance of the centre
							- drawback being white's invasion of the 7th ranks