请教af1几个问题

Kuntakimp

1.Illegal shift - a player is not in motion but is not set before the snap; more than one player is in motion at the snap; or after more than one player was moving (shifting), all eleven players have not been motionless for one second. Referee signal: two arms in front of chest, palms open and down, with the elbows out to the side, moved away from chest. Penalty: 5 yards from the previous spot.

其中,a player is not in motion but is not set before the snap;r after more than one player was moving (shifting), all eleven players have not been motionless for one second.各是何意? in motion具体指什么,什么才叫做in motion?

另外,关于intentional grounding的规定,十分复杂,能否解释一下:

Intentional grounding - a forward pass is thrown intentionally incomplete so that the passer avoids loss of yardage or to conserve time. Note that there is an exception that allows a snap received directly from the snapper (i.e. not in shotgun) to be immediately 'spiked'.
NFL penalty: 10 yards or spot of foul, whichever is farther from the original line of scrimmage, and loss of down. If the foul occurs within the endzone, the play is ruled a safety.
NCAA penalty: Spot of foul and loss of down.
NFHS penalty: 5 yards from the spot of the foul and loss of down.
In NCAA and NFL, if the quarterback has moved outside of the area between his offensive tackles (the "tackle box"), there is no foul for grounding the ball if the quarterback throws the ball past the line of scrimmage.
Referee signal: both hands held out flat, facing each other, in front of the referee, moving down together diagonally roughly from one shoulder to the opposite hip.

In the NFL, if any of the above fouls (except "Illegal Formation") occur with less than a minute remaining in the half and the clock running, then a 10-second penalty is also assessed. The 10-second penalty does not apply if the clock is stopped when the ball is set for play and will not start until the ball is snapped, if the team on offense with time-outs elects to use one in lieu of the runoff, or if the defense declines the runoff (which prevents a team from committing fouls to intentionally run out the clock). In addition, the game clock will run once the ball is placed. If such a runoff occurs with 10 seconds or less remaining, the half automatically ends. Since the enforcement of the 10-second runoff, only one NFL game ended automatically due to a false start with less than 10 seconds remaining (in 2005 between Arizona and St. Louis). A pre-season game in 2006 between Houston and Kansas City had the first half end automatically due to an intentional grounding foul with less than 10 seconds left.

af1

motion是指球员（通常是后场球员）在列阵完毕之后，开球之前/之时的移动；而shift是指两名或以上球员在开球前同时移动。

a player is not in motion but is not set before the snap这条，set position比较难解释清楚，可以认为就是进攻的准备姿势（作出set position之后除了motion一般不能再有动作），比如球员的躯干和两臂有动作之类的。

after more than one player was moving (shifting), all eleven players have not been motionless for one second这条应该很好理解，就是字面意思，如果有两名或以上球员同时移动，那么开球前所有球员必须motionless至少一秒钟（即不能两人同时移动后，一人停下set position，然后开球时另一人继续在移动in motion）。

intentional grounding是指四分卫在面临sack压力的时候将球传向不可能有接球手接到的地方。例外是，在pocket之外，如果将球扔过开球线，那么即使那个方向没有人，也不会被判intentional grounding。pocket应该不用解释了，至于具体判罚就是字面意思。
需要区别的是spike，即QB拿到球立刻把球砸到地上，这是停表的一种方法。

Kuntakimp

after more than one player was moving (shifting), all eleven players have not been motionless for one second这条应该很好理解，就是字面意思，如果有两名或以上球员同时移动，那么开球前所有球员必须motionless至少一秒钟（即不能两人同时移动后，一人停下set position，然后开球时另一人继续在移动in motion）。
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我觉得这表示很怪,如果有两名或以上的同时移动,因为球队只有11人,显然应该说成:all 10 players have not been ....; 另外,这样的表述岂不是与分号前的"more than one player is in motion at the snap"相冲突?
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关于intentional grounding的疑问,到不是在你所述的上面,而是在惩罚上,就是这句:
In the NFL, if any of the above fouls (except "Illegal Formation") occur with less than a minute remaining in the half and the clock running, then a 10-second penalty is also assessed. The 10-second penalty does not apply if the clock is stopped when the ball is set for play and will not start until the ball is snapped, if the team on offense with time-outs elects to use one in lieu of the runoff, or if the defense declines the runoff (which prevents a team from committing fouls to intentionally run out the clock). In addition, the game clock will run once the ball is placed. If such a runoff occurs with 10 seconds or less remaining, the half automatically ends. Since the enforcement of the 10-second runoff, only one NFL game ended automatically due to a false start with less than 10 seconds remaining (in 2005 between Arizona and St. Louis). A pre-season game in 2006 between Houston and Kansas City had the first half end automatically due to an intentional grounding foul with less than 10 seconds left.

af1

首先规则规定开球时是允许有一名球员在motion的。如果只考虑这一点，那么“两人同时移动后，一人停下set position，然后开球时另一人继续在移动”这个情况本身并没有违反motion的规定，开球之时也只有一名球员在motion。表述为（两人移动-->其中一人停，另一人不停，继续移动-->在另一人移动中，开球）——违反illegal shift。

合法的情况是，在两人同时移动过之后，如果想要在开球时保持有人motion，就要求这两人（以及包括场上其他9人）必须首先都全部静止至少一秒钟，之后才能继续开始motion。表述为（两人移动-->两人都停-->其中一人重新开始移动-->在该球员移动中，开球）

any of the above fouls是指进攻方(excep illegal formation)之外的犯规，应该是有上下文表述的。对于这些犯规，如果犯规发生在半场的最后一分钟，并且开球之前并没有停表（即前一档结束时为活球），那么犯规方将额外（除原有罚码外）被罚去10秒钟。在以下情况下，这10秒钟将不会被罚去：开球之前处于停表（及死球），或进攻方选择使用一个暂停，或防守方放弃该罚时（避免进攻方故意犯规消耗时间）。另外，判罚完毕后，一旦球被裁判放下，比赛时间将重新开始走动（即后续犯规都将会被罚时）。如果犯规时比赛剩余不足10秒钟，但需要罚时，那么该半场将自动结束。