here in Women's World Championship 2015 -round 4, Koneru recklessly played 25..f6 ,try to find what she has missed :
http://en.lichess.org/RCylWJOD#50
and here the continuation with same idea, again ,white to move :
http://en.lichess.org/RCylWJOD#56
http://en.lichess.org/RCylWJOD#50
and here the continuation with same idea, again ,white to move :
http://en.lichess.org/RCylWJOD#56