For Pep Guardiola, that record signing Riyad Mahrez did not sparkle during the opening months of this season was down to information overload.
The Manchester City manager insisted that hammering the homework, learning quite what was expected in his front three, would prove more beneficial in the long run.
He has probably been proven correct in that regard already and the £60 million forward's performances are steadily improving.
Mahrez, who kept Leroy Sane out of the side in the derby, was pivotal in both of City's first two goals before he trotted off and replaced by the German just after the hour. And on both occasions his role was straight out of the Guardiola playbook.
In the build-up to the first, Mahrez saw play developing with Raheem Sterling on the left and just stopped, standing on the edge of Manchester United's box for either a cutback or second ball. His marker, Luke Shaw, appeared preoccupied with the Algerian, even though Bernardo Silva was flying on his outside.
Shaw knew of Bernardo's whereabouts but Mahrez's loitering troubled him. Less than a second later and Bernardo was squaring for David Silva to score the opener.
Mahrez's role in the second was more overt and again indicated his growing understanding of how Guardiola wants his attackers to operate. City broke in midfield and rather than widening the pitch, the 27-year-old opted to take Shaw inside with an off the ball run.
It gave the prowling Sergio Aguero space to aim for, completing a give and go with Mahrez before slamming beyond David De Gea. The blur of movement with which they are renowned was evident and Mahrez has now bought into those unusual darts not many other teams see or perfect.
Guardiola is reaping the rewards of affording Mahrez time to settle, to study videos and generally learn the ropes.
He started just two Premier League games before being chosen ahead of Sane for the goalless draw at Anfield against Liverpool on October 7. That day ended in regret, Mahrez skied a penalty towards the end, but he has not looked back since.
His penchant for cutting in off the right remains but the starting position is a key difference from his spell at Leicester City.
Asked in September about the bedding in process, Guardiola said: 'He's not just here for a few months. We have never had any doubts about his quality of commitment. He will adapt quickly because of that mentality.'
It gives Guardiola yet another option and lightens the load on both Sane and Sterling, who suffered from playing every week last term. Six goals in all competitions is not a bad return from nine starts and eight from the bench.
Mahrez was key to City beating United and Guardiola will certainly have noticed