Introducing The Forecheck, The Globe's home for 2017-18 NHL predictions
Edmonton Oilers fans, it's time to start freaking out.
With less than half the season left, the Oilers are running out of time to salvage their year and make a second consecutive playoff appearance. Edmonton's chances of reaching the postseason have plummeted to 13.6 per cent, down from 67 per cent at the outset of the season, thanks to a recent rough patch.
In other words, the Connor McDavid-led squad will need something close to a miracle to reach the playoffs.
Those playoff odds weren't plucked out of thin air, either. They come from The Forecheck, The Globe and Mail's new destination for data-driven NHL predictions.
Developed over the course of a year by a team of journalists and data scientists, our model draws on roughly 2,000 variables to generate the most accurate hockey forecasts out there. Updated daily, it tracks each team's chances of winning games and making the playoffs.
The Forecheck builds on the work of several academics and hockey bloggers, including that of a former University of Ottawa student who wrote his master's thesis on how accurately one can predict hockey games.
Now on the Florida Panthers' amateur scouting team, Josh Weissbock didn't pick winners using his own hockey knowledge or gut instinct. Instead, like The Globe, he used reams of data and developed a predictive model.
Mr. Weissbock's model was accurate in predicting 59.8 per cent of games. "We found it interesting that regardless of which features we used in our model, we were not able to increase the accuracy much higher than 60 per cent," he wrote in his thesis.
That was the benchmark when The Globe started experimenting with NHL predictions. Our model not only hit that target, but surpassed it. (Current probabilities in this article were tallied on Monday morning.)
Now, 60 per cent may not sound like much. But hockey is not an easy sport to forecast. NHL games are relatively low-scoring affairs in which luck plays an undeniable factor. A team, for instance, can dominate play in regulation only to lose in a shootout.
There appears to be, Mr. Weissbock wrote, a "theoretical upper bound" of about 62 per cent for single NHL game predictions. (It's worth noting that Mr. Weissbock got closer to the limit using another approach.)
The Forecheck is, fortunately, not far below the upper limit. But getting there wasn't easy.
To develop our model, we needed to collect as much historical NHL data as possible. We ended up with about three decades' worth and partnered with data provider Sportradar. Data scientists at The Globe then rigorously tested a variety of models. Some of these produced single-game accuracy in the neighbourhood of 56 per cent or 57 per cent. That's not ideal. Home teams in the NHL win about 55 per cent of games. If we couldn't attain a healthy premium over the lower bound, our model would not have been worth publishing.
Eventually, we settled on a combination of two different approaches. First, we predict individual game outcomes using something called a neural network. Then, to calculate playoff odds, we use those game predictions to simulate a full season 100,000 times. (You can read a more detailed breakdown of our model and methodology here.)
Our predictions can vary greatly by team. If you're keen on predictions for the Vegas Golden Knights in its inaugural season, The Forecheck has been exceptionally accurate to date. Not so for the Calgary Flames. So far, our model has had a hard time predicting whether they'll win or lose; in fact, if we took the opposite of our model's predictions, we'd do fairly well in predicting their game results.
The Forecheck's long-term forecast of playoff teams is more accurate than our game-by-game predictions. For last season, a previous version of our model correctly picked 12 of 16 playoff teams before a single regular season game had been played.
And yet, as the season progresses, playoff probabilities can shift dramatically. Take the Toronto Maple Leafs: Coming off a strong season and postseason appearance, the Leafs had a 38.2-per-cent chance of making this season's playoffs, based on our preseason forecast. Their chances have since soared to 81.7 per cent.
In other cases, teams projected to make the playoffs have solidified their position. The Boston Bruins, Nashville Predators and Tampa Bay Lightning are three examples that went into the season with great playoff odds and now are virtual locks to reach the postseason.
As for the Oilers, making the playoffs isn't impossible – yet. According to The Forecheck's simulations, in 100,000 permutations of the regular season, there are 13,582 versions in which they clinch a spot in the postseason.
In fact, there's a version in which they rally to close out the season with 101 points, putting them near the top of the league. One version – in 100,000.