(A single team could hold possession of the ball for an entire half, neither achieving a goal nor forfeiting possession of the ball, simply by alternating between periods of incremental gain in field position and instantaneous large losses of field position as by a reverse-pass.)
Unless I'm misunderstanding you, losing yardage via negative legal plays like a reverse pass would not help a team hold possession indefinitely. For example, if on 1st and 10 the team runs a reverse that loses 20 yards, they are now faced with 2nd and 30 yards to go. Thus, they must still advance 10 yards beyond the original line of scrimmage in order to retain possession.
However, you left out the actual way they might retain possession indefinitely -- penalties. If, after said failed reverse, and now facing the 2nd down and 30 yards to go, the defense commits a penalty that results in less yardage gained than the previous loss (basically, anything other than pass interference on a long pass attempt) but awards a 1st down to the offense, the offense could conceivably continue to reset the downs (via the penalty) while not gaining any total yardage.
Yeah, To be honest, I have only a vague grasp of the rules of football. I forgot that yards to a down are counted from the original line of scrimmage at the first down.
Now, let's do a big of light Googleing. Ah, here we are:
If a team started a drive on their own 1-yard line, took 4 downs to make a first down every time, got just enough every time to get the first down, allowed the play clock to nearly expire before every play, took 5 seconds to run each play, never threw an incomplete pass, and the clock never stopped... that would mean 1 play was run every 50 seconds. It would take 4 plays to get to the 11-yard line, 4 more to get to the 21-yard line, etc, for a total of 40 plays to get a touchdown. These 40 plays would take 2,000 seconds, or 33 minutes, 20 seconds. However, even if the drive started at the beginning of the game, or the beginning of the second half, the drive would end at the end of the half, for a maximum of 30 minutes.
So from a practical standpoint, it looks like you can indeed hold posession of the ball for an entire half, thus allowing for only two "regular" commercial breaks (end of quarter and 2 minute warning) and forcing 8 TV Timeouts.
Haha, Nebraska Furniture Mart.. Picture an Electronics / Home decor store that's about the physical size of 2 home depots put together. They sell everything from electronics to appliances, furniture, rugs, etc. Most of what they sell undercuts shitty places like Best Buy to the tune of several hundred dollars.