I understand that spiking the football is a time management technique in American football, but I don't understand why there is no penalty (e.g. intentional grounding) associated with it?
This is actually a special rule case.
Section 2 Intentional Grounding
Item 3: Stopping Clock A player under center is permitted to stop the game clock legally to save time if, immediately upon receiving the snap, he begins a continuous throwing motion and throws the ball directly into the ground.
So you may spike the ball to stop the clock if you do so immediately after receiving the ball. However:
Item 4: Delayed Spike A passer, after delaying his passing action for strategic purposes, is prohibited from throwing the ball to the ground in front of him, even though he is under no pressure from defensive rusher(s).
Thus waiting to do so is considered intentional grounding.
Because it's specifically permitted by the intentional grounding rule.
Rule 8, section 2, article 1 of the NFL Rules:
Item 3: Stopping Clock. A player under center is permitted to stop the game clock legally to save time if, immediately upon receiving the snap, he begins a continuous throwing motion and throws the ball directly into the ground.
The NCAA has a similar rule (rule 7, section 3, article 2 of the NCAA rules):
ARTICLE 2. A forward pass is illegal if:
e. The passer to conserve time throws the ball directly to the ground (1) after the ball has already touched the ground; or (2) not immediately after controlling the ball.
So spiking is legal only if the snap was not fumbled, unlike the NFL.
Many years ago in the NFL, no one spiked the football because it was illegal to do so. If a team used up all of their time outs, the only way they could advance the ball AND stop the clock was to run out of bounds. This caused offenses to abandon using the middle of the field, for if they did (and they had no time outs), they ran the danger of running out of time. The defense knew this, so they focused their attention to protecting the sidelines, making it even more challenging for the offense to advance and stop the clock.
So what changed? The desire for more close games. When spiking the ball to stop the clock was made legal, it allowed teams unlimited amounts of short "timeouts". Now a team could use all of the field (instead of just the sidelines), knowing that they could stop the clock once they spiked the ball. The clock might still run after a catch is made, but once the ball is spiked, the clock is stopped, and time is saved. College football has the added benefit of the clock stopping when first downs are made late in either half, then the offense must spike the ball when the clock is restarted.
A forward pass that does not pass the line of scrimmage will be considered intentional grounding UNLESS it is "a pass that lands in the direction and the vicinity of an originally eligible receiver," and therefore has a realistic chance of completion.
A "pass" thrown directly in front of the passer immediately after the snap meets this definition of "a realistic chance of completion," based on the placement of the tight end and two running backs prior to the snap. The fact that the quarterback has intentionally "spoiled" his chances of completion by "fast-passing" or "spiking" the ball, does not affect this.
After these (and other pass receivers move), the question of intentional grounding will be considered on a case-by-case basis based on where the players actually are.
None of these answers explain why, just that its allowed. Yes, we understand that. The reason that its allowed is because everyone was trying to get the offenses to score more and this allowed clock management and first downs but penalized simply throwing the ball away (not scoring...). In the end its a ridiculous rule differential and only promotes offense and holds defenses. This is why Peyton can throw 55 TDs and we broke scoring records weekly in the NFL in 2013. Gone are the days of the Iron Curtain and The Monsters of the Midway. Unfortunately its too risky to make a tackle or touch the QB. So just let them score and hope we can score more. That's the new era of the NFL. Remember when passing was rare? Neither do I but ask your father...
here is my interpretation. it looks like an OR situation, not an AND. (as I originally thought) passer must have eligible receiver nearby (i.e. "realistic chance of completion") OR (not AND) be out of the pocket and throw the ball at least to line of scrimmage. (lengthy throw) so this is what I will go with. BUT, I feel like, in last night's game, with 0:08 sec left in 4th quarter, pass was thrown out of bounds to stop the clock. yes the pass was far enough, but I recall the passer just took a couple steps back. I would argue he was still in the pocket, so this "in the pocket" aspect is kinda hazy, or was it not required?