Table 1.
Approved balls in events.
Table 2.
Basic information of nine table tennis balls.
Fig 1.
JSV-H1000 table tennis hardness tester.
Fig 2.
M0633 table tennis ball elasticity tester.
Fig 3.
Mean ± SEM of hardness coefficient at pole and equator of the seam balls.
(* Significant difference at equator compare with celluloid ball; +Significant difference at pole compare with celluloid ball; # Significant difference between pole and equator; *: P < 0.05; **: P < 0.01; ***: P < 0.001).
Fig 4.
Mean ± SEM of hardness coefficient of the seam and seamless balls.
Table 3.
P values in Holm-Sidak’s multiple comparison t-test in hardness.
Fig 5.
Mean ± SEM of bounce height of nine types of tested balls.
Table 4.
P values in Holm-Sidak’s multiple comparison t-test in bounce height.
Fig 6.
Correlation between coefficient and bounce height.
(a) contained with seam and seamless balls; (b) only contained with seam balls.