The biggest opening weekend of all-time? Who would have thought?

On Thursday, in a straw poll of studio execs, Deadline received three different answers in regard to Jurassic World‘s domestic opening: The predictions were $115M, $125M and $135M. The thought that Jurassic World would make $172M+ and push Universal Studios past $1B at the 2015 B.O. would have been a ballsy projection — $145M tops according to one distrib analyst.

And then Jurassic World‘s grosses swelled, hour by hour, day by day. By Friday late night, the Steven Spielberg-produced movie was ranking third on the all-time openers chart behind The Avengers ($207.4M) and its sequel Avengers: Age Of Ultron ($191.3M). By Saturday, it was primed to beat Ultron, and as Sunday lingered it was clear the dinosaurs were set to tear off Avengers’ tights for the all-time record, called today at $208.8M.

An associate remarked to me this morning, “The projections were as reliable as the presidential ones on last night’s Veep finale.” So why were some B.O. forecasts off as much as $94M for Jurassic World? Get your box office nerd glasses on and we’ll explain.

‘Jurassic World isn’t a drop-off movie for the kids, but their parents want to see it too.’ — Uni distribution president Nicholas Carpou

Tracking typically wears the dunce caps in these off-kilter prediction scenarios. However, distrib chiefs sincerely swear NRG, Screen Engine and Marketcast’s systems aren’t broken, and as one forecasting insider asserts: “We’re not paid to predict box office, rather identify pockets of strength, threats and opportunities in the marketplace for the studio. … It’s a five-week journey with daily phone calls.”

When total awareness starts hitting the mid- to high-90th percentile range, and unaided awareness gets into the 40% range with first choice in the 30% realm — all of which were the case with Jurassic World — many studio distrib execs admit it becomes hard to predict just how far above $110M a film will climb in the course of its FSS. This might seem like a canned response, but mathematically it’s true per a B.O. market study guru: Once a film starts tracking beyond $110M, the tracking model breaks down. Why? Statistical tracking is based on previous cases and examples, the bulk of which exist in the middle of a data sample. Hence, when it comes to predicting a $15M-$50M opener; there’s a better chance for precision. There are a bulk of films to draw from in regard to comps. The higher echelon ($110M+) and lower end of the spectrum (less than $10M) are where it becomes challenging, with fewer B.O. scenarios to pull from. Only 24 films have grossed over $110M.

Heading into the weekend, comparisons were hard to find for Jurassic World. The best was Man Of Steel, which bowed during the same frame as Jurassic World two years ago and racked up $116.6M. Like Jurassic, it was a title being rebooted from a dormant, storied film franchise.

There were other holes in Jurassic World‘s tracking that contributed to its initial lowball estimates, and they’re the common industry gripes. For example, tracking doesn’t measure real-time response; most services poll three times a week and do so before the Thursday late-night shows. When the Friday tracking report comes out, it doesn’t reflect the vibe of the previous night’s sneaks, rather the audience’s interest during on early Thursday. Young kids under 12 aren’t part of the tracking samples, nor are families as a whole, and it was that group who showed up in droves for Jurassic World. Universal distribution president Nicholas Carpou told Deadline on Sunday, “Jurassic World isn’t a drop-off movie for the kids, but their parents want to see it too.” Given the multi-generational interest in Jurassic World, some believe that tracking’s inability to pulse kids and families hindered a better prediction on the grosses (that’s why it’s a challenge to put a finger on the opening of Disney family pics). Furthermore, millennials — the smartphone generation — are fickle. Between the time they are polled earlier in the week and the weekend, they can change their mind entirely in terms of attending the movies with their friends.

Also prompting lower pre-weekend estimates for Jurassic World was the fact that it was trailing Age Of Ultron ($191.3M) in unaided awareness (42% to 53%) as well as in men’s first choice: Ultron posted 54%-55%, while Jurassic Park was charting 39% in guys under 25 and 34% over 25. In hindsight, box office analysts sayUltron posted higher tracking figures since it was the kickoff film of the summer without any competitive titles in its way. Weighing down on Jurassic World’s tracking numbers were the other competitive films in the summer marketplace.

So as various execs and and analysts around Hollywood drew their own estimates, what truly happened with Jurassic World is that it became a beast unto itself. That’s when the film started over-indexing and beating everyone’s expectations. And the catalyst for the WOM heatwave can be pinned squarely to social media — which, unlike tracking, captured auds’ need-to-see vibe. Adds another Universal insider: “When you go into the weekend, you are armed with your expectations based on historical data, relying on movies released during the same time period as well as assessing different variables in the marketplace. But when the film gets a chance to be itself and grows through the weekend, you lose your historical data.”

A prime example of this scenario occurred with Ultron. It seemed as though the first Avengers would have served as the quintessential comp for Ultron — until the sequel smacked into the punching gloves of the Mayweather-Pacquiao fight during the first weekend of May. The lack of die-hard sporting events this weekend worked to Jurassic World‘s advantage: It was culturally the only event that Americans wanted to see. Sunday night’s Game 5 of the NBA Finals between the Golden State Warriors and Cleveland Cavaliers, despite its stellar 20.5M viewers, would have been more of threat if it was a New York/Boston vs. Los Angeles faceoff, per B.O. pundits. Ditto, for Saturday’s Stanley Cup Final battle between the Chicago Blackhawks and Tampa Bay Lightning — too regional to disrupt the Indominus Rex.

And as Uni execs watched hourlies rally for Jurassic World, word-of-mouth took off like a velociraptor barreling through the woods. According to social media monitor RelishMix, YouTube views for Jurassic World from its opening through Sunday were at 38M vs. Furious 7‘s 33M. The top Jurassic World spots were registering views on par with Furious 7 and the re-post rate for Jurassic vids on YouTube was 45 to 1 (the average is 9 to 1). The dinosaurs clearly had fans in a trance. On Saturday alone, the Jurassic trailer pulled 1.4M YouTube views. The official trailer for Jurassic Park on Universal’s YouTube channel counts a total of 66.6M views, beating Furious 7’s 61.6M. Twitter hashtag #JurassicWorld peaked at 63K on Sunday after building for seven days; 3X higher than Furious 7. Heading into the weekend, Rentrak’s social media index PreAct clocked the WOM for Jurassic World at 98%, which not only means that the conversation for the film was very high on social media, but that it was positive too.

Wow @prattprattpratt congrats on an amazing opening weekend my man #JurassicWorld — Jeremy Renner (@Renner4Real) June 14, 2015

Says RelishMix’s lead social strategist Marc Karzen: “Surprise polling 500 or even 5,000 people about a film that they may or may not want to see doesn’t correlate to box office well. It’s a qualitative response of how much they want to see a movie (sequel) or if the marketing is memorable. But what’s more powerful is how thousands and millions of people share trailers with their community, or not, on multiple social channels. That shows intent (to buy a ticket) and if the movie exceeds expectation, as Jurassic World did, the Internet and box office explodes”.

And once the word was out on Jurassic World, it was all about keeping up with the Joneses.

Observed one studio box office analyst: “When a movie over-delivers and reaches that zeitgeist fever pitch, people feel like they can’t miss out. This even goes back to Twilight (opening $69.6M) and the first Hunger Games ($152.5M) — movies that over-delivered on tracking. With everyone more connected, there is a pack mentality among moviegoers more so than ever before.”