The spin effect indicates the ratio of spin (rps) to speed (km/h).
This ratio influences the bounce behaviour of the ball and the necessary adjustment reaction of the opponent.
The values measured with the app always refer to the deviation from the neutral value (2.21 rps/km/h), which is indicated as 1 = neutral.
Spinny (>1.4):
The incoming ball has significantly more rotation than speed in relation to each other. In this case, the opponent must adjust their stroke (racket angle), e.g. "close" when blocking against a spinny topspin. Due to friction on the table, the incoming ball bounces flat and faster, it "kicks".
Neutral (0.4 to 1.4):
The incoming ball has a "normal" ratio of spin to speed, which approximates the natural rolling behaviour of the ball. The opponent can return the incoming neutral ball without adjusting their stroke (bat angle). The bounce behaviour of the incoming ball on the table is hardly affected.
Speedy (<0.4)
The incoming ball has slightly more, the same or even less rotation than speed.
In this case, the opponent must adjust their stroke (bat angle), e.g. "open" when blocking against a speedy topspin or counterattack.
Due to friction on the table, the incoming ball bounces higher and slower.
Calculation examples (at 45 km/h):
1.4 spinny: 45 * 2.21 * 1.4 = 140 rps
1.0 Neutral: 45 * 2.21 * 1.0 = 100 rps
0.4 Speedy: 45 * 2.21 * 0.4 = 40 rps