How long is the play clock in reality?

[ncwingman]

End of the first quarter, clock is running and shows 40.2 seconds when the 40 second play clock starts. Does A have to run a play before the end of the quarter?

At first glance, that seems obvious. Yes they do. 40.2 > 40, therefore the play clock will expire before the game clock does.

However, under normal circumstances, how many back judges throw a flag for delay of game after exactly 40.000 seconds have elapsed? There's usually a second delay, benefit of the doubt if the snap happens "at zero". Furthermore, when does the foul occur? Is is a) when the play clock hits zero, b) when the BJ acknowledges that the play clock is at zero, c) when the BJ sounds his whistle and throws the flag? If there's any sort of human reaction time involved in the discussion, it would be impossible for the delay of game penalty to be called prior to the expiration of the period -- unless you want to put 0.2 seconds back on the clock? Many game clocks can't do that.

If the difference in the clocks was more than a second, then I would argue the opposite. You can reset a game clock to 1 second, and all game clocks will show 1 second (not all show tenths -- arguably none should, but that's a different rant). Even if human reaction time is slow, there is a notable difference in the times and it's fixable.

Philosophically, I would argue that if there is less than a second difference between the game and play clocks, the offense does not have to run a play prior to the expiration of the period, even if the play clock expires first -- due to the impracticality of timing our game to fractions of a second.

Who strongly disagrees with me? I'm sure you're out there.

[CalhounLJ]

I'm with you. We go by full seconds. .2 is not a full second.

[bossman72]

If you have 2 visible play clocks, you have to go by what you see.  You will ruin your credibility if you and the coach clearly see a difference between game and play clock and you don't call DOG.

Also, try to have tenths turned off by the GCO if possible.

[Legacy Zebra]

If you have 2 visible play clocks, you have to go by what you see.  You will ruin your credibility if you and the coach clearly see a difference between game and play clock and you don't call DOG.

Also, try to have tenths turned off by the GCO if possible.

Agreed. I don’t know about NFHS, but NCAA specifically says that the clock shall not display tenths of a second. I also don’t believe the human eye/brain can accurately and reliably pick out exactly which tenth was showing when the play clock started. 

But to the actual question of the OP, you said it. 40.whatever is more than 40. If the play clock started with 40.something, the play clock will officially end before the game clock. But it would be a lot easier to communicate that if it just read 41 instead of 40 and change.

[AlUpstateNY]

Agreed. I don’t know about NFHS, but NCAA specifically says that the clock shall not display tenths of a second. I also don’t believe the human eye/brain can accurately and reliably pick out exactly which tenth was showing when the play clock started. 

But to the actual question of the OP, you said it. 40.whatever is more than 40. If the play clock started with 40.something, the play clock will officially end before the game clock. But it would be a lot easier to communicate that if it just read 41 instead of 40 and change.

Absolutely agree, displaying 10ths of a second are TOTALLY UNNECESSARY, during a football game and accomplish NOTHING, aside from potentially starting mindless arguments. 

[MAFBRef]

In Massachusetts, we have been instructed that if the clock shows tenths of a second, it is to be treated by rounding up. In this example, we would treat as 41 seconds on clock. With that being said, only 1 school in the state uses a visible play clock, so only the back judge knows exactly when he started the play clock after the prior down.

[refjeff]

Game clock and play clock are two different things.  What the game clock shows is irrelevant.

In Ohio a visible play clock is operated by someone not part of the officiating crew, usually in the press box, but occasionally on the sideline.  I prefer sideline.  Our mechanic is to look at play clock until :00 and then the LOS.  If the ball has been snapped it is not a foul.  I do not know what fraction of a second it takes to refocus my eyes from the play clock to the ball, but it is not instantaneous.
 
If there is no play clock the BJ uses his ReadyRef/RefSmart.

In subvarsity games we still use the old 25 second rule, and that is not looked at too closely unless one team is trying to consume time. 

[HLinNC]

What play clock shows 1/10's?  I've not seen one.

[MAFBRef]

Play clock only shows full seconds. Was referencing game clock showing tenths.

[Rich]

I am of such mixed opinions on having a visible play clock.  In competitive games, it would be amazing.

Last night, we had 2 lower level running clock games (running clock is 35 point differential after the first quarter here).  We ran the clock from mid 2nd quarter in both games.  I worked H the first game and R the second (I work R on Fridays and honestly wish I had stayed on the sideline last night).  Had the B called a DOG in a 50-point game against the losing team with the clock running, it would've been unfortunate, but with a visible clock he would've had no choice. And we have games like that occasionally on Fridays too where I know the B is stretching the clock, with my full support.

[Rich]

Play clock only shows full seconds. Was referencing game clock showing tenths.

And those have no business showing tenths, either.  This isn't basketball.

[dammitbobby]

I am of such mixed opinions on having a visible play clock.  In competitive games, it would be amazing.

Last night, we had 2 lower level running clock games (running clock is 35 point differential after the first quarter here).  We ran the clock from mid 2nd quarter in both games.  I worked H the first game and R the second (I work R on Fridays and honestly wish I had stayed on the sideline last night).  Had the B called a DOG in a 50-point game against the losing team with the clock running, it would've been unfortunate, but with a visible clock he would've had no choice. And we have games like that occasionally on Fridays too where I know the B is stretching the clock, with my full support.

This is where good play clock operators can be really valuable... good ones will understand the game and slow walk the clock when needed.  I've actually seen them pause the clock for a few seconds in the middle (oopsy!) and then start it back up... and I've seen PC operators stop it at one, when the situation dictates it (when Team A is down by 40 and struggling to get a play off.)  Team B coach can complain all he wants but honestly it's pretty rare, and even if he does, reminding him of the score, and that everybody wants this over ASAP so no one gets hurt, usually takes care of it.

And even with a visible PC, in those situations, a good B can milk it even more.  And R can usually find a reason to pump if necessary. 

[Etref]

I am of such mixed opinions on having a visible play clock.  In competitive games, it would be amazing.

Last night, we had 2 lower level running clock games (running clock is 35 point differential after the first quarter here).  We ran the clock from mid 2nd quarter in both games.  I worked H the first game and R the second (I work R on Fridays and honestly wish I had stayed on the sideline last night).  Had the B called a DOG in a 50-point game against the losing team with the clock running, it would've been unfortunate, but with a visible clock he would've had no choice. And we have games like that occasionally on Fridays too where I know the B is stretching the clock, with my full support.

Many a time in a lower level blowout game, I have instructed the coach to inform press box to turn off play clock. Never had a complaint