Its not nebulous to anyone who isn't mired in dualistic thinking that either things are quantifiable digits or they're crap.
Yes, it's possible to have "it" for a while and then lose it. Absolutely. That's the nature of it. "It" is generally a combination of synergistic and complementary traits, habits, skills, mentalities, and motivations that can propel an individual or a team to great achievements. It can come from the existing personalities in the room as combined in a different way around a specific cause. It can just be a burning desire to win that combines harmoniously with the ability to do the right things at the right times. "It" is a blend of champion qualities that can wax or wane because they are so elusive. "It" comes mostly from the mind.
You may not want to hear this, but the human body is linked to the human mind, and the human mind is a vastly complex function of only partially understood neurological functions. Much of what we do is possible because we have basic tasks stored in deeper parts of the brain, which allow us to perform higher level tasks without having to recount the exact steps of all the pedantic little components. We learn to tie our shoes when we're young and we never really think about the steps later. Where did that awkwardness and conscious manipulation of fingers and strings go? It became what people inaccurately call "muscle memory", which is really just storage of automatic processes in deeper parts of our brain so that we can concentrate on other things. The more we practice and heap new skills on top of others the better we become at even the most complex tasks. We cut neural pathways like water creating a channel down the side of a mountain. That is how mastery is achieved, usually through directed and intense practice over a long period of time. And that is also how choking becomes ingrained...when we learn bad habits and mentalities and imprint them in our minds through repetition and intensity (intense emotion aids imprinting).
This sounds like having a strong mental game and team chemistry. Certainly those things exist and play a big role in hockey, no arguments here.
But those items don't account for the flukier elements of hockey. Sometimes a player blindly fires the puck toward the net and it goes in off a leg. Sometimes a player shoots a puck around the boards and it bounces randomly to the slot against all odds. Sometimes a goalie saves a puck with the knob of his stick, something that is never practiced. Things happen that are not under anyone's control and have huge impacts on the game. These non-repeatable items can be quantified in approximate terms and unsurprisingly hockey and baseball tend to have the biggest elements of random chance.
It's not magic but it can appear that way when a master is at work. A classical pianist does not have to think about playing the notes. A basketball player simply reacts to the flow of the game, and the basket. Kobe Bryant has described the zone in excellent terms, including how everything just became "one noise". Old time athletes used to call it "the trance", or "going unconscious" or "lights out". It's really just "getting out of your own way" and letting those channels in the mountain flow.
The reason this is important is because having "it" often means getting to a stage where you simply TRUST your abilities and let them loose without a shred of conscious direction. There is no sense of doubt or "I don't know what to do". There is only flow and being in the moment. Everyone does this during the day,
but not everyone can call on it when it matters or under pressure. When a person can turn on this ability during clutch moments he has "it". When a team can inspire and push each other into these flow states, especially at the end of a game 7, they have "it".
"Clutchness" has been shown time and time again to not be a repeatable skill across mostly every sport. Certain players have made clutch plays, but they haven't done it with a frequency that is outside of their normal performance in "regular" situations.
Teams that don't have "it" lose those game 7s time and time again. And they blame "nebulous" **** like luck.
They're 3-7 in Game 7s in the Ovechkin era. Even giving the Capitals a 55% chance of winning each game (and this is almost surely a high estimate on average) this is a more than reasonable statistical outcome. Their Game 7 record alone isn't good enough to explain them lacking "it" when skill levels and simple chance can adequately describe it.
Performance psychology is not nebulous, it's real. Every single high level athlete will tell you about it, if you ever meet one. You won't find it in your stat sheets but it's the most important thing in all of sports, and it's why sports psychology trumps analytics. Without the former you can't have the latter, and if someone can improve his mental game he can buck his statistical trends. It's also why a player can put up numbers in one environment and not another, which makes the value of some statistics suspect.
So yeah, those teams found "it" for a time. It doesn't mean you have "it" forever. It takes work like any other skill.
Why aren't there any chronically choking teams in basketball? Who is the NBA equivalent of the Capitals, Sharks, Blues, Sabres, Canucks, Senators, etc.? Surely the mental game in basketball is just as important and surely clutch moments exist just as they do in hockey. Chemistry, teamwork, intangibles, etc. are all just as important most people would agree. There must be players and teams that wilt under the pressure of the playoffs and others that can repeatable rise to the occasion, right?
Or perhaps the mostly deterministic nature of basketball and the chaos inherent in hockey can explain these discrepancies in choking/rising to the occasion better?