#3 Momentum at the beginning of the second half
Barcelona were under attack in the first half and looked more likely to concede than their arch-rivals. Add to that Sergi Roberto's red card on the cusp of halftime. The game demanded precise and perfect tactical decisions from Valverde, and he did not let his side down.
The way Barcelona came out in the second half was commendable. They did not allow Real Madrid to settle and attack. Instead, they took control of the proceedings.
This stage of dominance did break Madrid's flow and hampered their attacking game to some extent. What could have been a rout was turned into something quite favourable for themselves.
The Blaugrana dominated possession and further went on to take the lead via a beautiful Lionel Messi strike. And in centre of all this, there was one man, Andres Iniesta. Iniesta pulled the strings from midfield for Barcelona for the last time in an El Clasico.
He kept the ball, moved forward, and strung together passes after passes to allow Barcelona keep the possession of the ball. The home side in the past have had the luxury of hogging the ball for the sake of it. On this occasion though, it was quite mandatory for them.