#1 The "Fluid Four" system
To complete the "fluid four" system, either one of Pogba or Herrera join the front three on the counter. These four now play short passes amongst themselves while moving cleverly at the same time. The clever movement along with the technical ability of these four allows them to draw defenders into one area of the pitch.
As seen in the above image, the four are able to draw as many as eight Tottenham defenders which leaves a huge gap behind them for Valencia to exploit.
Once the fullback is in the right position, either one of the four plays a simple pass to him and the entire Tottenham defence scrambles in a panic to press Valencia.
From there, the United fullback can attempt a shot himself or try to find one of the four who has found space in between the panicking Tottenham defenders.This exact situation was replicated during Herrera's winner.
After winning the ball back, De Gea launched it upfield for Lukaku, who flicked it on for Sanchez in support. After dribbling past one defender and finding space on the left flank, Sanchez played it back into Lukaku whose underwhelming touch luckily fell to Ander Herrera who was darting into space in behind the Spurs defenders.