Over a period spanning more than 100 years, head coaches, managers and tacticians have collaborated to form the rule book on how to conduct yourself as the figurehead of a football club. "Guidelines," if you will.
Marcelo Bielsa took the rule book and ripped it to shreds the moment he started his endeavour to learn everything about our beautiful game, and his methods are far from ordinary.
Let's take a look at the Argentine's illustrious career and see why he employs the very strangest of tactics.
"El Loco" revealed
They don't call him crazy for nothing. Throughout his tenure in football, he's done some odd things to gain the upper hand.
Before we even delve into his atypical tactical system, just have a look at some of questionable things Bielsa has done to date.
This summer, the manager was warned by the Athletic Bilbao board after an altercation with the builders, labelling their work on the club's training ground "sloppy."
He supposedly paces the width of the pitch before every game in order to refine his tactics down to the very last detail, while last season he drenched certain random areas of the San Mames turf to stop Barcelona from being able to play their tiki-taka quite so effectively.
So we know by now he's not your average, run-of-the-mill coach. There aren't many modern-day managers who drive the length of the country to find undrafted talent or ask teenage boys to climb trees and spy on his opposition during training.
Marcelo Bielsa comes from an old-school era of coaches who want absolute control mixed with meticulous preparation for every possible outcome.
It's evident that "the mad professor" sits down before each game and plans for every eventuality, every potential substitution and every injury.
He switches between two and three central defenders on the pitch depending on how many strikers the opponent has on the pitch. Bielsa is an advocate of the spare-man philosophy in defence, meaning he always wants one centre-half free to sweep up and not be hindered by man-marking.
Last year, in the UEFA Europa League semifinal, Sporting threw on an extra attacker whilst chasing the game late on, thus moving to a 4-4-2. Within three minutes, Bielsa had Borja Ekiza stripped and ready to come on as the third central defender in order to retain a spare man at the back.
Against Barcelona's false-nine system last season, the Argentine had Fernando Amorebieta man-mark Lionel Messi wherever he went on the pitch, leaving Javi Martinez to marshal the back line and intercept Cesc Fabregas' forward runs.
When manager of Chile, he usually utilised an incredibly demanding, physically draining 3-3-1-3 that requires the most immense sense of versatility.
To think he used it with a national team who barely get the chance to play together on a regular basis is astounding, and the player roles delegated are tough to carry out.
His philosophy of using attack-minded defenders shone through here, as he deployed defensive midfielders on the outside of one true central player to shuttle up and down the pitch. Later on, we'd see Martinez deployed in the same fashion for Bilbao.
The second line of three contained something almost akin to a narrow full-back on either side, and even then he still employed two wingers higher up the pitch.
For all his meticulous planning and obsession over preparations, one of the strangest things about El Loco is that he doesn't change his tactics according to the personnel available.
Where other teams may alter how they play if without a key figure, Bielsa simply replaces them with another and commands they perform to the same level.
This was particularly evident at Bilbao last season, as without Martinez, Los Leones weren't able to get going. Yet, instead of adjusting the system and placing more of an emphasis on Fernando Llorente, for example, he simply instructed the technically limited Ander Iturraspe to take up the mantle.
Despite his methods being both entertaining and impressive, the lack of leeway he awards to players is astonishing.
This is a man who, aside from being a tactical genius, is inflexible with his system, demands titanic efforts from his players, sabotages pitches, screams at builders and hires spies to sit in trees.