Average age of 36

Siegemund has methodically planned her week in Rome. She demolished Alexandrova in three sets last night with an arsenal that leaves no room for rhythm in flat shots: a low slice that stays below the knee, moon balls that change the height of the shot, drop shots that force a 6'1" player to sprint to the net. Alexandrova never found the shoulder-height she needed. Plíšková is built on the exact same model: a flat, fast shot, dependent on rhythm, vulnerable as soon as the ball doesn't come where she expects it. The Alexandrova lesson is directly applicable tonight.

Plíšková, for her part, survived two three-set matches this week, against Bouzas Maneiro and then against Cristian, conceding dozens of break points before finding the mental strength in the closing stages. The champion hasn't faded; she's gradually gaining momentum, and her serve, when it's turning, is becoming a weapon that disrupts Siegemund's system. If the Czech player gets her first serve right tonight and gets above 70% of her serves in, the German won't have the same space to create chaos. That's where the match will be decided, in this duel between Plíšková's serve and Siegemund's unsettling patience.