There are four units in football -- offense, defense, special teams and the officials -- and only one of them can rule absolutely.
The officials can rule absolutely in some instances, with no review or challenge of their decisions. Their word is final, even when evidence shows that they're wrong.
That's one of the things we learned in the Detroit Lions' gut-wrenching 19-17 loss to the Baltimore Ravens. Justin Tucker's league-record 66-yard field goal won it as time expired.
Immediately after the game, video replays surfaced showing that the play clock appeared to have expired one play before the kick. That would have been a five yard penalty against the Ravens.
Had all things remained the same, Tucker would have been forced to attempt the field goal from 71 yards, or the Ravens would have been forced to attempt a Hail Mary pass into the end zone.
I'm offering a solution that would eliminate another officiating error on the play clock.
Among the other things we learned include the following: Losing the way the Lions did creates arguments on what could have been done differently to prevent the outcome resting on a final-play field goal; and how despite going 0-3, the Lions have competed hard in starting their season against three of the NFL's better teams.
We start with the officials:
They are easy targets and take far too much blame for supposedly making an impact on the outcome of games. That is particularly the case on judgment calls on plays such as pass interference.
Why didn't the ref see a defensive back pulling a receiver's jersey? Because he didn't see it. Simple as that.
A play-clock violation is different. It's cut and dried. Time either expired or it did not. Evidence Sunday showed that the clock may have expired on the play in question, and that the Ravens should have been assessed a five-yard penalty.
My suggested solution: Copy the NBA's shot clock. It goes off when the 24 seconds a team has to get off a shot have expired. There is a frame of lights around the two backboards. The lights go on, and a buzzer sounds when 24 seconds have expired.
Questionable plays are reviewed, and there is no grey issue. The ball has left the player's hand or hasn't before the lights go on and the buzzer sounds.
My suggestion for the NFL: Put lights at the top of the uprights on the two goal posts. If the lights go on before the ball is snapped, it's a penalty.
If that system were in place now, it would not have guaranteed anything for the Lions. The Ravens still had time to run a play before Tucker attempted the field goal, but an incompletion or a gain shorter than five yards would have made for a longer field goal than the 66-yarder Tucker made.
At least it would have been clear cut, with no controversy.
That's my contribution to world peace.
Different strokes: I get the discussion on play calls on the Lions' last possession that set up their go-ahead field goal, and whether rushing three was the right defensive call when the Ravens had fourth and 19. Jackson had time to hit Sammy Watkins with a 36-yard pass that put the Ravens in field-goal position.
My opinion: There was nothing wrong with either call.
What I would have done differently was on the kickoff after the Lions took the lead with a field goal.
View photos from Detroit Lions vs. Baltimore Ravens Week 3 game at Ford Field on Sunday, Sept. 26 in Detroit, MI.
The clock was the Lions' asset. Instead of kicking the ball out of the end zone for a touchback I would have ordered a kickoff inbounds to force a return that would eat up time.
Special teams have been a strength for the Lions. That was a time to use that strength.
Power up: Head coach Dan Campbell said after the game that he would learn a lot about his team from playing the Ravens because of their toughness.
The Lions passed that test in what was the third game in a brutal start to the season. They went 0-3, with losses to the 49ers and Packers before Sunday's defeat by the Ravens.
All three teams are playoff contenders and currently have 2-1 won-loss records.
The payoff is on winning, but the evidence at this point is that Campbell has a team that competes hard.