What happened at Madrid Open
Elena Rybakina disputed an electronic line-calling decision during her three-set victory against Zheng Qinwen on Sunday at the Madrid Open. When Zheng's serve was called in as an ace despite a visible ball mark on the clay court appearing to show it was out, Rybakina gestured at the mark and confronted chair umpire Julie Kjendlie. Rybakina asked the umpire to come down from her chair to inspect the mark physically, but Kjendlie refused and stated she had to go with the electronic line-calling system's decision.
Rybakina's frustration and loss of trust
Rybakina expressed her frustration immediately, telling the umpire: 'This is not a joke. The system is wrong. This is not a joke. It is not touching. It is absolutely wrong.' After the match, she elaborated to reporters, calling it 'kind of a stolen point' and stating she would not trust the electronic line-calling system. She emphasized the point was frustrating because the mark was visible right in front of her, making the system's contradictory ruling particularly difficult to accept.
Why clay courts create this dilemma
On clay courts, tennis balls leave visible marks that do not always tell an accurate story. The clay surface is 'live,' affected by the amount of red brick dust, weather conditions, and shot trajectory. Tennis balls compress when they land, creating marks of various shapes and sizes that can be illusory. While the electronic line-calling system has a margin of error of only a few millimeters, the visible marks on clay can be misleading, creating a fundamental conflict between two different knowledge systems.
Pattern of controversies
This is not the first time electronic line-calling on clay has sparked disputes at Madrid Open. The previous year, men's player Alexander Zverev faced a similar controversy and was warned for unsportsmanlike conduct after taking a photo of a disputed ball mark with his phone. He claimed there was a 'defect in the system,' noting a discrepancy of four to five centimeters between the ball mark and the electronic call—far beyond the system's stated margin of error.
Broader adoption of electronic line-calling
As of 2026, Hawk-Eye electronic line-calling is used at three of the four Grand Slams and across all men's and women's tour events above the 250 level, including the Madrid Open. The Australian Open, U.S. Open, and Wimbledon have all replaced human line judges with the system. Only the French Open has retained traditional line judges, continuing to use ball marks on clay to determine calls. 
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