Polished one minute, tripping over himself the next; David Luiz is destined to remain one of football's great unsolved riddles.
Some of the most lauded managers, Jose Mourinho and Antonio Conte among them, have toiled trying to figure him out, and have never quite cracked it. The complexities that have made Luiz one of the most enigmatic players in the Premier League era remain.
When Kevin De Bruyne's pass skimmed off his thigh and into Raheem Sterling's path on Wednesday night, you could almost hear the collective groan from north London.