Keys Unlocks Her Toolshed

Madison Keys' racquet switch, from Wilson to Yonex, has opened new abilities and possibilities late in her career.

MELBOURNE, Australia — Veteran agent Max Eisenbud was skeptical when he heard one of his longtime clients, Madison Keys, was thinking about a late-career shakeup.

“I’m historically really against changing racquets,” Eisenbud told Bounces this week.

Tinkering, Eisenbud believes, undercuts the confidence that comes from stability.

“I would always get worri…