“Aggressiveness, a combination of power and spin, extremely strong footwork, consistency and great forehand.” So much for Iga Swiatek’s sporting strengths. But the ex-player and now TV expert Barbara Schett sees other advantages that make the difference. “Iga is a player who has not only trained in tennis, but also invests a lot of time in the mental area. She goes out there and feels like she’s invulnerable.”