India, Nov. 17 -- Jannik Sinner slumped on the bright blue court after the final point and lay flat on his back for a good few seconds. The last time he did that was after the final point of the 2024 Australian Open, to become a Grand Slam champion for the first time. In his three major triumphs after that, he simply lifted his arms in celebration.

This reaction was not typical of Sinner. This stage too was not the theatre called Grand Slams.

What, then, could explain the gush of emotion from an otherwise mild-mannered Italian on winning the season-ending ATP Finals? Sinner, after all, had also gone all the way last year, equally ruthlessly without dropping a set, and in front of his home fans in Turin. Been there, done that.

Perhaps, ...