Playoff Primer Part 2/2 (Regular Season Success)

Happy NHL Playoffs Eve!

If you haven’t checked out part 1 of the primer, you’re missing out on an exploration of NHL home ice advantage in the regular season v. playoffs. In part 2, I’m going to be exploring the relationship between regular season success and playoff success across the NHL, NBA and NFL. In other words, how much “parity” do we see between the playoffs and regular season? In this case, what I mean by “parity” is the relationship between regular season and playoff success. I capture this phenomenon by looking at the average regular season winning% of playoff teams in the NFL, NBA and NHL (data courtesy of hockey, baseball and football reference):

Average Regular Season Winning% of Playoff Teams

What does this mean? Since the NFL only has 12 total playoff teams compared to the 16 of the NBA and NHL, it is to be expected that the average NFL playoff team is well above average. However, when we compare the NHL and NBA over the past 18 years, the average NBA playoff team tended to be better than the average NHL playoff team – until 2012. This trend shifted quite drastically in 2012, with the average NHL playoff team outperforming the average NBA playoff team in the regular season.

What if we limit our scope from all playoff teams to the regular season winning% of conference finalists (the final-4):

While the NFL still reigns supreme with the highest average regular season winning% of their Conference Championship participants, they did fall below average twice in the past 18 years (2008 and 2010). Just to refresh your memory, the 2008 NFL NFC Championship featured the 9-6-1 Philadelphia Eagles and 9-7 Arizona Cardinals. That year, the final-4 boasted a combined 65% winning percentage, lowest in the league’s past 18 years, but still more than the average NHL Conference Finals team. Speaking of which, the NHL was below average (and at the bottom of the list) every season except 2012. This featured the (somewhat) anti-climatic Conference Finals that included two #1 seeds (Pittsburgh and Chicago), the 4th best team in the league (Boston) and Los Angeles. In other words, the NHL appears to have the most unpredictable outcomes in the playoffs of these three leagues. But wait there’s more…It’s time for the main event: The difference between regular season winning% of the average final-4 team relative to the average playoff team.

Difference Between Regular Season Winning% of Final-4 and Average Playoff Team

The impact of this chart is to identify the “parity” within each of the leagues by calculating the difference in regular season winning% of final-4 teams to their respective leagues’ average winning% of all playoff teams. There’s a few conclusions that we can draw from this chart: (1) The NBA is the most predictable sport in this regard. This should come as no surprise to anyone that follows basketball – the best teams seem to almost always advance to the conference finals, with 2 notable exceptions: 2006 and 2009. In 2006, while Detroit and Cleveland occupied the top-2 seeds in the East, there was a major shocker out west with the 8th seeded Warriors upsetting the Mavs in the first round. Something similar happened in 2009, with the top-seeded Cavs upset in the second round by Boston and the 2nd-seeded Mav’s getting dunked on (pun intended) by the Spurs in the first round. While a couple of 1/2/3 seeds being upset isn’t really that exciting for the NHL or NFL, for the NBA it’s the only evidence of relative unpredictability that we have. (2) The NHL has the most unpredictability in the playoffs of any sport. It is rare (like 2012) that successful regular season teams advance to the conference championship. On four different occasions (2009, 2011, 2013 and 2016), the average final-4 team was actually worse than the average NHL playoff team. The only other league to accomplish this feat was the NFL, who holds the record for most chaotic playoff of the past 18 years in 2008. (3) Speaking of the NFL, there’s a lot more variation than other sports, , which is a product of a single-elimination playoff format.

In sum: The NHL and NBA are more predictable (for very different reasons). The regular season is less predictive of a deep playoff run in the NHL and more so for the NBA. Whereas, the NFL is just a total crap shoot year-to-year. With 24 teams in the NHL Playoffs this year, we should actually expect some chaos based on what we’ve seen in previous seasons.

Playoff Primer Part 1/2 (Home Ice Advantage)

Welcome to Stanley Cup Playoffs Week!

Beginning on Saturday, August 1 at 12:00 PM EST, the New York Rangers and Carolina Hurricanes kick off the insanity of this year’s COVID Olympics, also known as the Stanley Cup Playoffs. All games are being played at Rogers Place (Edmonton) and Scotiabank Place (Toronto), with Western teams playing at the former and Eastern teams at the latter. That means that only two teams will actually enjoy all the luxuries of “home ice advantage” – Toronto and Edmonton. The rules regarding home ice advantage will remain the same as any other season, with the higher seed afforded the benefits of “home ice advantage” in 4 games of the best-of-7 series (3 of the 5 in the first round).

These benefits include:
(1) Last change – The home team makes player substitutions after the visiting team between stoppages of play
(2) Faceoffs – The centre from the visiting team must put their stick on the ice first
(3) Rink familiarity

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NHL Scoring Model Part 1: Even Strength Goals

This is the first part of many posts that is part of a larger project. The ultimate goal of this project is to develop a statistical model that will allow me to determine the probability of wins and losses for NHL teams. I am hesitant to say that I will be able to predict who will win or lose, but rather construct a model for success (i.e. if certain conditions are met, a team is more likely to win). As hockey fans, we recognize certain events during games that alter the momentum of one team. The model that I am developing is an attempt to capture important aspects of the game, such as shooting the puck or winning faceoffs. The data is sourced from war-on-ice.com, and has been organized per team by game spanning from 2005-2014 (totaling over 25,000 rows). As of right now, I expect to examine several game situations including but not limited to: even strength, power play, shorthanded and 4v4.

The first order of business is examining even strength goals. I think that everyone can agree that the absence of 5v5 scoring diminishes the ability of a team to be competitive. Along with goals against, scoring goals is one of the most important events that occur during a hockey game. Recently, the most common explanation for goal scoring is puck possession. It has been theorized that teams with high puck possession rankings tend to be more successful. This seems intuitively true, since the team who possesses the puck has more chances at scoring than the team without the puck. Since there is only one puck on the ice, it is a zero-sum game: whoever doesn’t have the puck cannot score. The two most common measurements of puck possession are Fenwick and Corsi. In simple terms, Corsi measures all shots taken, whether they miss the net, blocked, or on net. Fenwick also measures shots taken, with the exception of those blocked.

In other words:
Corsi = All shots directed toward the net
Fenwick = All shots directed toward the net – Blocked shots

Continue reading “NHL Scoring Model Part 1: Even Strength Goals” →