What do managers really constitute down during games?
The achromatic books, nan hastily scribbled notes earlier a corner, a glimpse to constitute down an important observation.
They tin beryllium nan quality betwixt triumph aliases defeat, pinch a tactical move having nan imaginable to beryllium nan game-changer.
Jose Mourinho was a keen taker of notes, nan 'Special One' advocated nan value of it during his 2nd spell astatine Chelsea.
"I publication nan first half, I return my notes, I hole my interventions astatine half-time based connected nan notes and wherever I consciousness I tin thief my players. So, I make nan notes successful bid to beryllium fresh to make my changes," he revealed.
Rather than a notebook, England Under-21 leader Lee Carsley uses an iPad during games arsenic he adapts pinch nan technology.
"I've sewage a batch of pictures connected there," he said. "So, there'll beryllium patterns nan squad do, nan opposition. I'm ever checking that.
"Sometimes erstwhile I'm looking astatine it, I'm looking to spot if nan guidance are doing nan movements I deliberation they mightiness do - because I cognize what we'll do if they are, because we've already planned for it.
"Or if there's thing different, past I'll beryllium making notes astir that. I'll constitute down a batch of notes, but astatine half-time it'll beryllium 3 points.
"The players tin retrieve that benignant of thing. The remainder of nan unit will spell astir and do different notes that possibly nan [whole] squad don't request to hear."
During caretaker spells astatine Coventry, Brentford and Birmingham earlier successful his managerial career, Carsley took notes successful a book - but he has transitioned to screens while astatine nan FA.
"There is decidedly thing astir penning it down connected paper," added nan erstwhile Republic of Ireland world midfielder. "I astir apt look backmost connected my books much than I do connected my iPad. It's a spot easier, I tin spell backmost to nan book astatine immoderate point.
"It was ever a pad and pen erstwhile I started. The bully point astir nan iPad is we've ever sewage a strategies committee truthful if immoderate of nan lads do travel over, I tin move it quickly and they'll spot it, alternatively than maine penning it down.
"But I've ever taken notes, they're really beneficial. I astir apt don't look backmost connected them arsenic overmuch arsenic I should, but we usage it for nan debrief aft nan game. So what we thought would happen, did it happen, and double-checking it."
Technology has changed nan measurement clubs are capable to analyse nan crippled and, therefore, speak to nan players.
Fans successful nan correct spot will ever spot a nine analyst, laptop successful hand, sprinting down nan steps successful nan guidelines and disappearing down nan passageway a fewer minutes earlier half-time.
But sometimes managers request their notes for clarity.
"For me, it's not truthful overmuch during nan crippled aliases astatine half-time I constitute things down, I did constitute thing down against Chelsea [a 1-0 conclusion successful March] aft nan triple substitution, which was erstwhile we changed building from a 5-2-3 to a 4-4-2," said Leicester leader Ruud van Nistelrooy.
"I wrote nan names pinch nan triple substitution, who is successful and out, what nan squad would look for illustration and who was going to play where. It was 3 subs and a alteration of structure, truthful it has to beryllium a clear picture.
"Other than that, I make much notes during nan week. You are battling for nan now, but I do look astatine nan mid-term early of nan nine and what is necessary."
In contrast, Wolves caput coach Vitor Pereira - who has led nan nine to nan brink of endurance aft taking complete successful December - likes his notes during a game.
He added: "I'm a feline pinch a napkin and a pen! Of people I person nan iPad, I do nan training, nan training plans, set-pieces and tactical organisation there, but I for illustration to write.
"Some tactical corrections, sometimes collective, sometimes individual. Half-time is simply a short time. When we get location I don't speak. The players travel successful pinch nan adrenaline and they request to remainder a bit.
"Afterwards I spell to nan committee and I effort not to person a batch of information, but nan cardinal information. Put connected what I've written and past I explain, 'we should do this to correct this', thing special."
It's not conscionable astatine nan apical of nan game, though, that this happens.
Stevenage leader Alex Revell follows suit. The 41-year-old, successful his 2nd spell astatine nan Lamex Stadium, relies connected nan craft.
He said: "The logic I return notes is I effort and support to nan principles of what we group successful nan game. So, for instance, if we want to build retired from nan back, who's doing it well, what problems is it causing us?
"If we want to press, what's nan property looking like? So I ever effort to make my notes not conscionable advertisement lib, but reactionary to definite situations.
"When you're really circumstantial pinch what you constitute astir nan press, build-up, transitions and you attraction connected things for illustration excessively galore turnovers, for instance, it's truthful clear that is conscionable 1 of your messages.
"It helps me, alternatively than conscionable being conscionable connected emotion, connected mistakes aliases definite situations successful nan game."