
Angelique Kerber has supplanted Serena Williams as the world number one since achieving a year ago's last, yet her frame has drooped in 2017 and she is in threat of losing top spot after Wimbledon.
The German, 29, plays Irina Falconi of the US in her opening match.
"I'm beginning from zero here," said Kerber. "My brain is step by step here, similar to a year ago.
"I...