We all like to give referees the benefit of the doubt. They undoubtedly have a very tough job and without the video replays that we all enjoy while watching the game on TV, it's little wonder that they occasionally make mistakes.
Sometimes, though, it's difficult to be so forgiving. Every once in a while, a referee will make a mistake that is so glaring that you wonder if the problem was that they didn't see the incident in the first place, rather than not being able to watch it over again.
Such indiscretions can be forgiven during a park game, but some such moments occur on the biggest stages of all, when league titles, relegation and World Cups are on the line.
Here are soccer's 20 most notoriously bad referee calls.
Back in 1980, Crystal Palace's Clive Allen struck a free-kick so sweetly that it hit the stanchion at the back corner of the goal and bounced back into play.
The Coventry defenders naturally went about their defensive business as if there was absolutely nothing to see here. They certainly fooled BBC commentator John Motson, who twice claims that the ball "hit the woodwork."
The referee and linesman come to the same conclusion, leaving a prepubescent Allen to bemoan, "Ah no, it hit the stanchion!"
Alan Hudson was the beneficiary of what was pretty much the opposite of what happened to poor old Clive Allen.
Hudson hit a shot that whistled past the outside of the post and hit the back stanchion, before bouncing back onto the pitch. Referee Roy Capey took one look and gave a goal.
This was despite the fact that Hudson didn't celebrate and Chelsea players could be seen lamenting the missed shot.
We're also not sure how Capey could have possibly explained how the ball could have gone into the net, hit the stanchion and then end up on the pitch, on the other side of the post.
If ever there was a decision that lives up to the stereotype of referees being joyless souls with nothing but icy hatred in their veins, it was this one.
In a match between Rangers and Hibs, referee Dougie Smith dropped his yellow card. Paul Gascoigne picked the card up and theatrically gave a booking to the referee as he returned it.
Smith didn't think the joke was particularly funny and having taken the card back, promptly booked Gazza for dissent. Way to make a name for yourself...
The Republic of Ireland were heading towards a penalty shootout in their playoff against France and the chance to qualify for the 2010 World Cup.
That was until Thierry Henry controlled a long ball with his hand, with all the adeptness of Michael Jordan, before crossing for William Gallas to score a winner for the French.
Swedish referee Martin Hansson gave the goal and in doing so, made an enemy of an entire nation.
There was no "Fergie Time" when referee Clive Thomas was around. Back in 1978, he awarded Brazil a corner in the dying seconds of their World Cup match against Sweden, only to not give them time to actually benefit from taking it.
Brazil stuck the ball in fairly promptly and Zico headed the ball home, only to find that Thomas had blown his whistle and ended the match.
The Brazilians protested, but the Welsh referee was already off on his way towards the tunnel, with the sort of intensity only witnessed from a British man when he has a pot of tea on the brew.
The fact that Tottenham's run without a win at Old Trafford continued until this season can be blamed on Mark Clattenburg, who denied Spurs a 1-0 win there back in 2005.
With the game almost over and 0-0, Manchester United goalkeeper Roy Carroll came out of his area to clear the ball upfield. The ball was knocked back into the United half, where Tottenham's Pedro Mendes was waiting to attempt an audacious lob over the goalkeeper.
To give Carroll some credit, he got back on the line in time to stop the shot. To immediately snatch that credit away, he made an attempt to catch the ball that was akin to my wife being thrown a box full of spiders.
Having fumbled the ball, it clearly went several feet over the line, before Carroll hooked it back into play and tried to pretend that nothing happened. Clattenburg somehow bought these unconvincing, straight-faced theatrics and ruled out the goal and with it, the win that Spurs deserved.
Referees are often fooled by a player diving, but you know you're witnessing something out of the ordinary when the commentators are laughing at the ridiculousness of a player's dive and the referee gives a penalty.
Emerson Acuna of Colombian club Atletico Junior was the culprit, as he played a one-two and then flung himself to the ground, despite having no defenders near him and being clear through on goal.
The Italians know a thing or two about referees being bribed, so if they call foul, then people should listen.
In the 2002 World Cup, Italy were the victims of a shocking display from referee Byron Moreno, during their Round of 16 clash with South Korea.
The Koreans, who co-hosted the tournament, were continually given gift-wrapped decisions from the official, which included awarding South Korea a dubious penalty, turning down a surefire penalty for Italy and disallowing a clear Italian goal.
As well as these major incidents, there was a string of smaller fouls that weren't given and South Korea eventually progressed, 2-1, to go through to the quarterfinal, where they were involved in further controversy...
It's almost impossible to conceive now that there was a time when Spain were unable to make it past a quarterfinal.
They fancied their chances against South Korea in 2002, only to quickly realise that Egyptian referee Gamal Ghandour was going to make life tough for them. Ghandour disallowed two perfectly good goals: an own goal from Kim Tae-Young and what should have been a golden goal by Fernando Morientes.
South Korea went on to win the game on penalties. The Germans eventually knocked them out in the semifinals.
How come when Spurs suffer a dodgy decision against Manchester United, Mark Clattenburg is always involved?
Nani fell in the area and appealed for a penalty. Clattenburg didn't give one, for some reason, nor did he give a free kick for the fact that Nani was by this time lying on the floor, cradling the ball like a baby.
Heurelho Gomes took the ball from Nani, naturally assuming that a foul had been given and placed the ball on the pitch, ready to take the free-kick. Nani then got up, legged it round Gomes and put the ball into an empty net.
According to Mark Clattenburg, this is an example of a perfectly good goal.
Who needs to spend money on an expensive striker when you can just get a ball boy to stick it in the net when the referee isn't looking?
Santacruzense of Brazil snatched a 1-1 draw with Atletico Sorocaba when a ball boy grabbed the ball after it had gone wide of the post, walked onto the pitch and side-footed it into the goal.
Astonishingly, the referee gave the goal. Who knows what he was looking at while all of this was going on? It certainly wasn't the ball.
The match between Bayern Munich and Nurnberg in 1994 was fairly important. Bayern were closing in on the title, while Nurnberg were battling against relegation. It probably wasn't the sort of match to make a huge mistake in.
Unfortunately, that's just what the referee and linesman managed to do. Bayern had a corner and Thomas Helmer was able to get a touch on the ball, but sent it wide of the post.
Linesman Jorg Jablonski stood on the opposite side of the pitch and, from his vantage point, thought that the ball had gone inside the post, dutifully giving the goal. As referee Joachim Osmers was unsighted, he went with the linesman's decision.
This goal is known in Germany as the "Phantomtor" and this has subsequently become the word to describe such instances.
Geoff Hurst is the only man to have scored a hat trick in a World Cup final, except for the fact that we all know that he only scored twice that day.
His second "goal" that afternoon in 1966 bounced down off the crossbar towards the line, but did it go over or not? Are you kidding? Clearly the whole of the ball did not cross the line.
Legend has it that it was the "Russian Linesman," Tofik Bakhramov, who decided that it was a goal (he actually came from Azerbaijan). England were 3-2 up and Hurst would score the fourth to secure a first and only World Cup victory for the host nation.
In the 1982 World Cup semifinal, Patrick Battiston of France found himself clean through on goal, with West German keeper Harald Schumacher racing towards him.
Battiston knocked the ball past Schumacher, only for the goalkeeper to jump into the air, twisting his body and smashing into the French substitute. He was knocked unconscious, damaged his vertebrae, lost three teeth and later slipped into a coma.
Referee Charles Corver did not send Schumacher off. Nor did he book him, or even give a foul. Instead, he calmly gave a goal-kick to West Germany, as if the incident was completely unintentional.
Referees who rule out goals when the ball has crossed the line make a lot of bad decisions. Or the opposite, when they give a goal when the whole of the ball has failed to cross the line.
At least in these instances, the ball is somewhere between the posts and beneath the bar. It's only the trifling fact of whether the ball has gone over the line or not that has baffled the referee.
Stuart Attwell, however, somehow managed to give a goal to Reading against Watford when the ball at no point seemed over the line, nor was on target. As "ghost goals" go, this is Attwell's "I see dead people" moment.
Some 44 years after Geoff Hurst's "goal" against West Germany, the Germans got their revenge when Frank Lampard inexplicably had a goal disallowed in their 2010 World Cup tie.
At least the Russian linesman had the excuse that there was some doubt as to whether the ball had crossed the line or not, while Lampard's shot was clearly well over the line.
The English claimed that the decision cost them the game, but considering that they were so outclassed in the 4-1 defeat, that shouldn't be taken too seriously.
In the 2006 World Cup match between Croatia and Australia, referee Graham Poll gave Croat Josip Simunic three bookings before finally sending him off.
Upon flashing the second yellow card, which should have, of course, been followed by a red, Poll was so busy arguing with Simunic that he appeared to completely forget the rules of the game.
Having had two yellow cards and somehow managing to escape being sent off, you might have thought that Simunic would have kept his nose clean. Instead, he picked up another booking and gave Poll an opportunity to rectify his mistake.
When you're already 4-0 down, the last thing you need is the referee giving the opposition a fifth for no discernible reason whatsoever.
Duisburg went 5-0 up against Frankfurt with a ridiculous goal that hit the crossbar and bounced back miles away from the line. Considering that the ball landed almost halfway out of the six-yard box, it's almost impossible to fathom how this could have been deemed a goal.
During a Scottish match between Dundee United and Partick Thistle, referee Les Mottram somehow contrived to make two huge mistakes.
First, he became the latest in a long line of referees to be confused by the stanchion when he failed to award Paddy Connolly a goal.
If that wasn't bad enough, Mottram then somehow missed the fact that as the ball bounced out of the goal, a Partick defender actually caught it, held onto the ball for a couple of seconds and then handed it over to the goalkeeper.
England really did sign a deal with the devil when that Russian linesman stated that the ball was over the line in 1966.
They've suffered numerous moments of bad luck in World Cups since, but perhaps none was more frustrating than the day in 1986 when Tunisian referee Ali Bin Nasser failed to notice that Diego Maradona had punched the ball past Peter Shilton to put Argentina 1-0 up in the 1966 World Cup quarterfinal.
The clues were there. It was unlikely that the 5'5" Maradona would outjump and head the ball past the 6'1" Shilton for a start.
Maradona proclaimed that the goal was scored via the medium of "a little with the head of Maradona and a little with the hand of God."