Page 67 - Enders_Game_Full_Book

"You're good," he said.
"None better. And you're going to learn how to do it."
Petra taught him to hold his arm straight, to aim with the whole arm. "Something most soldiers don't realize is that the farther away your target is, the longer you have to hold the beam within about a two-centimeter circle. It's the difference between a tenth of a second and a half a second, but in battle that's a long time. A lot of soldiers think they missed when they were right on target, but they moved away too fast. So you can't use your gun like a sword, swish swish slice-em-in-half. You got to aim."
She used the ballcaller to bring the targets back, then launched them slowly, one by one. Ender fired at them. He missed every one.
"Good," she said. "You don't have any bad habits." "I don't have any good ones, either," he pointed out. "I give you those."
They didn't accomplish much that first morning. Mostly talk. How to think while you were aiming. You've got to hold your own motion and your enemy's motion in your mind at the same time. You've got to hold your arm straight out and aim with your body, so in case your arm is frozen you can still shoot. Learn where your trigger actually fires and ride the edge, so you don't have to pull so far each time you fire. Relax your body, don't tense up; it makes you tremble.
It was the only practice Ender got that day. During the army's drills in the afternoon, Ender was ordered to bring his desk and do his schoolwork, sitting in a corner of the room. Bonzo had to have all his soldiers in the battleroom, but he didn't have to use them.
Ender did not do his schoolwork, however. If he couldn't have drill as a soldier, he could study Bonzo as a tactician. Salamander Army was divided into the standard four toons of ten soldiers each. Some commanders set up their toons so that A toon consisted of the best soldiers, and D toon had the worst. Bonzo had mixed them, so that each consisted of good soldiers and weaker ones.
Except that B toon had only nine boys. Ender wondered who had been transferred to make room for him. It soon became plain that the leader of toon B was new. No wonder Bonzo was so disgusted-- he had lost a toon leader to get Ender.
And Bonzo was right about another thing. Ender was not ready.
All the practice time was spent working on maneuvers. Toons that couldn't see each other practiced performing precision operations together with exact timing; toons practiced using each other to make sudden changes of direction without losing formation.