Let rule adopted for ball over the backstop
Source: Fessenden S. Blanchard, Platform Paddle Tennis, 1959
As play improved, balls were occasionally bounced over the 12-foot wiring, ending a rally and making it necessary to chase the ball for some distance. This was corrected when the APTA adopted a rule regarding balls bouncing over the backstop:
“A ball which lands in court of play and bounces up and over side or back walls should be considered a ‘let ball’ and the point replayed.”