The only players I've seen in online blitz that didn't know openings were the 1200s (i.e. complete noob). Anyone rated over 1700 will know openings and middlega

The only players I've seen in online blitz that didn't know openings were the 1200s (i.e. complete noob). Anyone rated over 1700 will know openings and middlegame and endgame and tactics and strategy. For blitz openings are essential and the difference between playing into a solid middlegame position in 10 seconds versus wasting one minute reaching an almost equal position.