"40-15, Rikkai Ohsanada scores."
After hearing the referee's decision, Seigaku's side exploded.
"How could Zero be beaten back?!"
"Did that Sanada commit a foul?!"
"What the hell is going on, Oishi?" Ah? Oishi Oishi!"
"Fuji, did you see clearly?"
"You must have seen clearly what happened to Sanada just now! Past? ”
It is impossible to foul, otherwise how could the referee declare that Sanada scored?
Nioh, who happened to catch this scene, looked at the two people on the court, taking in their expressions, and then looked at the specific situation of Sanada's catch point just now. Very good, it was a success.
"Great, great! The deputy minister used that trick!"
Different from the confusion of other viewers and the shock of Qingxue, Li Hai's side was full of people. My heart is clear and I am very excited.
Because they are all aware of Sanada’s obsession with Tezuka, everyone in Likai has been taking time to help Sanada develop special skills against Tezuka. Under such circumstances, it was in this case that the moves like thunder and darkness were It was developed two months ago, and they may be able to see these two skills in the game soon.
However, Tezuka’s domain and hard-earned limit are easy to break, but the zero serve is unsolvable to a certain extent. After all, the rule is that you cannot catch the ball before the tennis ball hits the ground, but Tezuka’s zero serve is But it is possible to make a tennis ball not bounce at all after it hits the ground. How can anyone score points?
Regarding this kind of serve that is 99% unsolvable, Nioh gave two probabilistic cracking directions for reference.
One is for the user himself, using a high-spinning powerful tennis ball in his or her own serving game to increase the burden on the opponent's arm, causing the opponent to make service errors and produce an imperfect zero-style serve.
Of course, this point was directly passed by Sanada. In Sanada's view, if the opponent chooses to play high-intensity tennis by overloading the body, then even if the injury is serious, it is the opponent's own choice. He has no right to interfere; but if he intentionally plays tennis that hurts his opponent's body, that would be despicable on his part. He doesn't care what others do, but he himself doesn't want to win in this way. Moreover, what’s the point of cracking the imperfect Type Zero?
The second point is about the tennis itself. You are not allowed to return the ball before the tennis ball hits the ground. Then return the ball when it lands. If the tennis ball does not bounce, then let it bounce.
The former operation can be done simply and roughly by shoveling the soil from the field, or you can calculate the time and return the ball at the moment when the tennis ball comes into contact with the ground. But the uncertainty of such an operation is too high and there are too many unstable factors. How can the referee determine whether it is in compliance with the regulations? Referees are human beings after all, not a high-precision machine.
This chapter is not finished yet, click on the next page to continue reading.
What about the latter? Is it possible to make a tennis ball that was originally rolling towards the net bounce back? The answer is - as long as there are principles to follow, there are countermeasures to break the principles, so everything is possible.
What is the principle of zero serve? This needs to be broken down and looked at step by step.
First of all, it is the initial force of motion that is common to all tennis balls and even all ball games, which is the push force exerted by the player on the ball through the center of mass. After this basic push force takes effect, the tennis ball will smoothly move along the direction of the force. move.
Next, based on the physical knowledge that applying a force deviated from the center of mass of the tennis ball, the tennis ball can both translate and rotate under the new force, players can play various rotations. ball.
Among them, there is a type of spinning ball that is extremely exploitable, and that is the backspin ball.
Based on the technique that the rebound angle of the backspin ball will gradually become smaller, players can control the tennis ball to make it land early when the tennis ball spins to a certain extent, and make the tennis ball land based on the force. Instead of bouncing back, it would roll forward close to the ground, or stop directly.
So, why does the rebound angle of the backspin ball gradually become smaller, and it can even move unreasonably close to the ground?
The physics knowledge involved in this is too simple. Most people know it, and that is Bernoulli's principle.
If this term is unfamiliar, then in other words: where the fluid flow velocity is high, the pressure is small, and where the fluid flow velocity is low, the pressure is strong. This common sense of physics that junior high school students are all familiar with is Bernoulli's principle.
As a tennis ball advances, the rotation of the ball will drive the flow of air. For a backspin ball, because the rotation angle is closer to the ground, the air flow speed above the ball is smaller than the flow speed of the ball, and the air flow speed below it is relatively small. Generally speaking, the flow rate is relatively large, so it will naturally produce a downward pressure on the ball, so that the tennis ball can hit the ground without bouncing.
On the basis of the above two steps, Tezuka exerted a vertical spin force on the tennis ball. In other words, his Zero Type was based on the Bernoulli principle. Within the control range, it experienced backspin and landed in advance, stopped at the landing point for a moment, and then spun and rolled in three steps toward the net.
Then the method to crack this serve comes out. The returner only needs to make the air flow above the tennis ball faster and the air flow below it slower, so that the tennis ball can bounce upward normally after it lands.
However, if you simply swing the racket over the tennis ball and accelerate the airflow above the tennis ball, it is obviously not enough, because the power of the empty racket cannot exceed the rotating tennis ball itself with substantial mass. Therefore, if the returner wants to return a zero, he must first cut off the attraction between the tennis ball and the ground before this step.
This is why Sanada’s return ball is accompanied by some dirt particles.Because after judging the landing point of the Zero, he rushed to the landing point of the tennis ball in advance, shocked the ground with the racket, brought up the dust on the field, and blocked the connection between the tennis ball and the ground in advance, and then cooperated with what was said before The spinning racket brings up airflow between itself and the tennis ball, including above the tennis ball, and accelerates the flow of air between the upper air and the direction of the tennis ball. As a result, the moment the tennis ball lands on the ground, it loses the close friction with the ground and the force of rolling toward the net, and is squeezed to the side with the higher air flow rate.
Of course, it is still like what I said just now [The power of an empty racket cannot exceed the rotating tennis ball itself with substantial mass], so even if this step is achieved, the zero serve will still not be like an ordinary tennis ball. The bounce is also very high. But for the side that returns the ball, even if it only bounces a centimeter, this so-called unsolvable zero has been broken!
"It seems that I still have to fight the real Tezuka in order to stimulate the deputy minister~" Niou leaned on his partner, his expression showing a little resentment, "Obviously I have been phantoming into Tezuka. I fought with him, but against my Type Zero, the deputy minister has never successfully used this move. Alas~ it hurts~"