1. Ancelotti's system relies too heavily on Marcelo's input: while Real Madrid is lucky to have such a gifted player in its roster, Marcelo cannot be the team's engine and primary playmaker. In the second half, the Brazilian player could no longer sustain the physical effort needed to push into the final third and his passes lacked incisiveness and accuracy. The glaring disconnect between the midfield and forwards following Isco and Modric's substitutions shifted the playmaking responsibility to Marcelo, thereby making the fullback easy to double-team and pressure into making an error.
2. The BBC needs to put away their chances: Ronaldo had a shot hit the crossbar, Bale shot just wide after having the ball land at his feet in a corner kick scuffle, and Benzema had two shots saved by Bravo. As often happens in these tense contests, the BBC's squandered chances came back to haunt them as they rarely saw the ball again in the second half.
3. The back line looked foolish in the second half: While Mathieu's headed goal was disappointing considering Ramos was marking him closely, Barcelona had no trouble slicing through Real's defensive line during the final thirty minutes of the match and could have scored were it not for off-target shots and Iker's interventions. Varane and Ramos looked lethargic as the MSN charged through the middle and Carvajal had a rough time of closing down Suarez. Real Madrid's back line looked like anything but a lock-down defense as the game spiraled beyond Madrid's grasp in the second half.
4. Madrid may have lost the league once more due to fatigue: remember last year when Real Madrid lost its lead at the top of the table thanks to defeats to Barcelona, Sevilla and Celta Vigo? Ancelotti's men looked like they were hauling weights in the second half given their inability to press let alone mark their opponents, and I fear Ancelotti's lack of rotations may be afflicting this team just as we head into the final stretch. We need James to return, Coentrão to hit form, and Lucas Silva to learn Madrid's system.