Football's laws are always evolving. In recent years, there have been changes to the kickoff, alteration to the punishment for "last man" fouls and the long-awaited rollout of VAR.
The rules and regulations have not adapted much in terms of clamping down on gamesmanship, and in a way, that is the point: It is not about breaking laws as such but more about pushing their boundaries in search of an advantage.
A popular description of these actions is "dark arts," but what are its major forms? Here are 10 examples.
The tactical foul
Remember that infamous Sergio Ramos challenge in the Champions League final that tipped the balance of the game toward Real Madrid?
No, not that one. Two years before he collided with Mohamed Salah, Ramos resorted to his most cynical to stop a breakaway by Atletico Madrid's Yannick Carrasco in stoppage time, with the score 1-1. With Antoine Griezmann to his left and Fernando Torres on his right, Carrasco swept forward in a three-on-one counter.
Danilo was the only Madrid defender between the attacking trio and Keylor Navas' goal, but then came Ramos, from behind the play, to wipe out Carrasco. From Atletico perhaps having a 50 percent chance of scoring, now they had a free kick in the centre circle. Real could reorganise, and there were only 30 seconds remaining.
In an era when counter-attacking is a crucial part of the game and teams attempt to press in numbers high up the pitch and risk their midfield being bypassed, midfielders in particular will look to foul because they know collecting a yellow card and conceding a free kick is better than allowing the break to unfold.
Jose Mourinho accused Manchester City of the practice last year, and while Pep Guardiola denied those suggestions in the club's documentary, "All Or Nothing," his assistant, Mikel Arteta, was heard telling City players to commit tactical fouls if necessary. Such an approach has been adopted as a fundamental part of defensive game plans, and "taking one for the team" has become acceptable. However, it is an area in which the punishment does not fit the crime; in a sense, overt fouling is effectively incentivised.
Messing with the man in the middle
Some home teams are effective at subtly influencing a referee's mindset, even before a single ball is kicked -- and sometimes postmatch, too. After his retirement, former World Cup referee Graham Poll suggested that one top European club presented him with a watch after every game, while another provided replica kits for all the officials' children.
Other clubs provide referees with a police escort onto the pitch, even if it is not strictly necessary. Does that make them less inclined to give decisions against the club that rolls out the red carpet?
Blocking off at corners
Germany's 7-1 victory over Brazil in the 2014 World Cup semifinals is one of the most famous results in football history, and while the majority of the victors' goals came from counter-attacks, their first came when an unmarked Thomas Muller volleyed in Toni Kroos' corner.
Why was Muller standing on his own? His marker, David Luiz, had been blocked off by Miroslav Klose, who ran straight into the Brazilian defender as Muller retreated to the back post. Germany's players insist it was not intentional, but either way, it showed the value of such blocking.
Although not a new tactic -- Mourinho's first Chelsea side specialised in it, and some amateur teams have even been doing it for years -- this form of block-off has become commonplace, and subtle, in recent seasons. Some clubs even employ specialist set-piece coaches to work on particular routines.
It is particularly effective against teams that defend man-for-man rather than zonally, but is the type of action that might become more scarce after the widespread introduction of VAR.
C'mon, ref! Make the right call!
Mourinho's complaint about City and their fondness for tactical fouling was itself a form of gamesmanship. It would be naive to think that referees are not only unaware of such comments but also unaffected by them. In this example, while the Man United manager might have had a point about City's tactical fouling, it was not his place to advise match officials.
Yet this never stops players from trying to critique referees on the pitch. Players have always gotten away with too much in terms of dissent, and it has become routine to see them crowding the referee when a decision goes against them. In big matches, particularly in La Liga over the past decade, the situation has become unacceptable, with an obvious prearranged strategy to apply pressure in the opening minutes.
Interestingly, this often comes after the referee has given a decision in favour of the protesting team. They do not protest heavily against a free kick being given the other way, for example, for fear of being exposed if the opposition take the set piece quickly. Instead, they insist that a foul should be accompanied by a yellow card. If the referee isn't paying attention, players will even wave imaginary cards to convey the message.
It is an ugly scene that arises because the referee usually cannot justify booking multiple players, but some kind of collective punishment -- even if that involves sending the manager to the stands, for he is responsible for the conduct of his side -- could help ease this problem.
Stealing yards at throw-ins
It is not the greatest footballing crime, but it is perhaps the most common. Not only are players liberal with where the throw-in should be taken, but they also readily creep up the touchline with the ball in their hands, gaining precious yards toward the opposition's goal.
This is particularly prevalent when "dummying" a throw; they stop, and then, with their second run-up, go far in advance of where they should have been. In a world where teams pressing opponents heavily toward one touchline has become a key strategy, an extra 10 yards can make a major difference to the significance of losing possession.
Of the 64 matches at this summer's World Cup (excluding those that went to extra-time) the shortest, in terms of the ball being in play, featured 45 minutes of football: Egypt vs. Saudi Arabia in the group stage. The longest lasted 67: Belgium vs. England in the third-place playoff.
The difference is remarkable -- one game was literally 50 percent longer than the other in terms of actual football -- and that gap influences the approach of underdogs. One of the Premier League's smaller sides, for example, would be delighted to draw 0-0 away to Manchester City. Clearly, such a result is likelier from 45 minutes of football than 67.
Teams have always wasted time when winning, but it is noticeable that some attempt to do so from the opening minutes, when the game is still scoreless: Throw-ins are delayed, goal kicks are taken from the opposite side of the 6-yard box, and players will waste as many seconds as possible to clamber to their feet having been fouled, for example.
The aforementioned statistics show that it makes a significant difference, and the effect of breaking the rhythm of the opponent -- even if the referee adds on extra time -- should not be underestimated, either. At some point, football might realise the extent of the problem and move toward the stopping clock prevalent in American sports.
The act of "simulation," or engineering contact
The diving debate has become increasingly complex. Simulation, in its starkest form, is against the laws of the game, but there are plenty of grey areas.
We have all witnessed situations in which an attacker has clearly been tripped or pulled in the box, only to do the "honourable" thing by not going down, and the referee has not awarded a penalty. Given that, can you blame forwards when they go down? However, such actions are only a small step away from exaggerating minimal contact, which is uncomfortably close to diving or entirely inventing a foul. Where do we draw the line?
Then comes the question of engineering contact. Some players, such as Crystal Palace's Wilfried Zaha, win penalties because of their trickery. There's nothing wrong with playing specifically for spot-kicks -- like, say, tempting a defender into a foul by leaving a trailing leg to be tripped -- but this is a short journey from actively making contact with opponents before falling to the ground.
The authorities have attempted to clamp down on diving by introducing retrospective suspensions, but that doesn't do anything to change the outcome of the game in which the offence occurred. VAR could help redress the balance in this area as well.
Rotational fouling, or sharing the dirty work
Mourinho has usually man-marked Eden Hazard when Man United have met Chelsea, with varying levels of success. The Belgian midfielder is so tricky under pressure that he inevitably wins free kicks from opponents, and once the defender has been booked, man-marking becomes a perilous job, as Ander Herrera found out in the 2016-17 FA Cup quarterfinal.
During the clubs' most recent meeting, it was notable that the first three fouls on Hazard were committed by different United players. Had the same one transgressed multiple times, he would surely have been cautioned. Instead, a combination of players was able to take one bash apiece at Chelsea's danger man.
Sometimes, when players raise a finger to signal it is their first foul, the strategy is obvious. Referees eventually get tired of the infractions and book a fourth or fifth offender -- typically, it seems to be the most minor offence that is punished -- but it remains a somewhat popular approach against tricky attackers.
The retro art of the "reducer"
Finally, we come back around to Ramos. His coming-together with Salah in the Champions League final was, on first viewing, a relatively innocuous incident in which a defender got his foot in to win the ball cleanly, after which the two players happened to tumble to the floor. It was only after watching replays that suspicion arose: Does Ramos deliberately lock his arm into Salah's, hauling the Liverpool man to the ground in such an awkward manner that he was forced to depart through injury? Only Ramos himself knows, but his track record suggests that he isn't unfamiliar with such tricks.
Peculiarly, this is the type of thing that is sometimes tolerated in England. Attempting to win a penalty is considered underhand, but overly physical contact -- not to injure a player but to "let them know you're there," which might make someone think twice next time they're in possession -- is considered fair game. In truth, though, it is the most blatant form of cheating on this list and something that is literally against the Laws of the Game, which cover unnecessary force that should lead to both yellow and red cards.
Perhaps that is the problem with policing gamesmanship: What is considered a disgrace in one place is acceptable elsewhere. A couple of law changes, as well as the introduction of VAR, might change things in some ways, but gamesmanship will always be part of the sport.