Lionel Messi still baffles Marc-Andre ter Stegen in Barcelona training, despite the German having had three-and-a-half years to work out the Argentine icon.
Messi is in the midst of another peerless campaign at Camp Nou, with 27 goals to his name in 33 games across all competitions.
Despite daily looks at Messi's technique, Ter Stegen is yet to work his team-mate out, and says he can understand why opposition goalkeepers are helpless.
"He is very intelligent and knows exactly where to put the ball," Ter Stegen told Sport of Messi.
"Sometimes journalists say that goalkeepers can do a little more when they play against Messi, but I see it in every training: it does not matter where you place yourself, he's going to shoot to the other side.
"He's smart: many other players shoot just to shoot, or for taking the ball off, but he does not.
"He calculates it in a special way: sometimes he puts it so soft that it seems easy to stop it, but it is not."
Barca are 11 points clear at the top of La Liga before Sunday's Catalan derby against Espanyol, with a Copa del Rey semi-final second leg and Champions League last-16 tie against an out-of-form Chelsea to follow this month.
Ter Stegen was Barca's Champions League goalkeeper when they last won the treble in 2015 and believes they are showing a similar standard this term.
"We are in a good moment," he added. "We have to maintain this concentration.
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"We must keep winning matches and do well in the Champions League, because there you depend on two games, and sometimes even one as we saw last season, that some teams scored three and four goals on us.
"And, of course, you have to be 100 per cent focused. But it is one of those seasons in which you have the opportunity to win titles. And that is what we want. In LaLiga we are very advanced and we want it to continue like this."