It's the intangible that is immediately visible when it's not there but where should teams look when all sense of confidence appears gone?
Although Broncos captain Corey Parker was adamant after his side's 48-6 loss to the Storm last week that "the confidence is still there" outside observers could only surmise when Melbourne scored three tries in the space of seven minutes midway through the first half that Brisbane were a team still looking for answers.
In all but a couple of games this season the Rabbitohs have played with effort but as was the case against North Queensland on Sunday they appear to be suffering a case of 'paralysis by analysis' and the harder they try the worse it gets.
For former NRL coach Matt Elliott the common denominators of teams who are down on confidence is that they are over-thinking everything that they are doing; moving away from knowing that they can do something to believing they can.
"The confidence comes from a thing called knowing," Elliott explained to NRL.com.
"If you're sitting there and beside you is a screw-top bottle and I asked you to open that bottle you'd be completely confident that you could do it. You don't believe you can do it, you know you can do it.
"If I asked you to open a bottle of medicine where you had to squeeze the edges and then push down before you turn it, you wouldn't be as confident that you could do it because you'd have to think about it.
"If you asked a rugby league player what they were thinking when they played their best game most of the time they will answer that they weren't really thinking, they were just doing what they know.
"You have to think in a game of footy but at the right times. When you're actually doing things and you're acting with confidence you're not thinking, you're doing what you know.
"While thinking is a foundation of confidence, it's the biggest thing that depletes it. And on the footy field at an elite level having to make lots of split-second decisions, if you're thinking about them, it's taking too long.
"One of the mistakes that we make as coaches is looking for different ways of doing things rather than better ways of doing things.
"Every time you get something new to do and you actually have to think about what you're doing, your attention is diverted away from doing what you know.
"The more you understand that you can do something and you know you can do something, that's where your confidence comes from."
While teams such as the Storm, Sharks and Cowboys currently execute at a level far superior to the rest of the competition Elliott has some encouraging words for fans who are struggling through their team's current losing streak.
Coaches will repeat ad nauseum that in order to turn things around they need to "stick together and keep working hard" and while there is an element of truth to that the best way to rediscover lost confidence is to find a way to grind out a win, however ugly it needs to be.
"It's not something that arrives miraculously," Elliott said.
"If you look at Brisbane, their talent hasn't evaporated, it's still there but their confidence and their energy is down and they're two things that go together.
"Energy is not about fitness. You get a lot of energy from confidence. Knowing the guy beside you is going to do his job, knowing your role and all that sort of stuff.
"Most of the time the teams that go through this dip in form, most of the time they don't just come back and all of a sudden it reappears and they smash teams. Most of the time they have to eke a win out, an ugly win, and they get two of them together...
"Winning brings confidence because it reinforces your behaviours. That's the other part of confidence, the other part of the formula, is actually getting your behaviours reinforced by victory."