Toss & Motion 發球 50% 成功來自拋球

50% of a successful serve comes from the toss
No stable toss = no stable serve
發球 50% 的成功，來自「拋球」
拋球不穩，發球一定不穩

拋球不是小細節，而是整個發球的起點。
The ball toss is not a minor detail, but the starting point of the entire serve.