When we look back at the 2017-18 Curling Season in another
5, 10 or 20 years, it may be remembered as a major turning point, leading to
dramatic changes in the sport.
The debut of mixed doubles at the PyeongChang Olympics could
draw new fans to watch and possibly even try on a slider and start-up the game
as well. Gold medals for Canada’s John
Morris and Kaitlyn Lawes in the Olympic Mixed Doubles, despite having joined
forces only weeks before, showed that talent and experience in big moments
outweighed the specialized skills of other countries at the new
discipline. It will be interesting to
see if players will continue to specialize in mixed doubles or if high
performance curlers will pursue both versions of the sport.
The other Olympic curling result for Canada may bring dramatic
changes to the qualification process. Failure
to medal will lead those who run Own the Podium to question if Curling Canada
should change the process to determine its representative every four
years. Canada has been inclusive, with
many teams receiving funding and allowing multiple paths to qualify through
competition rather than selection. We won’t
likely see Canada hand pick teams in 2022, but could there be a reduction in teams
at the next Trials?
John Shuster’s Olympic Gold medal could
lead to further expansion of the game in the Unites States. We could see increased
funding and TV exposure and greater sponsorship move the sport even further to professional
status. Jamie Sinclair’s win at the
Players Championship may not have reached the same audience, but the first ever
Grand Slam win for a US team will help curling grow and, along with Anna Hasselborg’s
gold medal, perhaps change how teams think about the game.
Team Hasselborg raised their play over the last couple of
years, winning the Gold medal for Sweden in South Korea. Jamie Sinclair reached new levels in a matter
of months, going 6-2 at the Players, against teams in which they previously had
a 3 and 32 record. Both teams (and Shuster
as well) have revealed that their success came with some contribution of using analytics. This past season may be remembered as the one
where curling with math moved from novelty to strategic weapon.
Let’s look at how we got here, what happened this past
season, and what we might see in the future.
The Past
In the ninth end of the 2005 Brier finals, five-time
champion Randy Ferbey faced a decision.
Tied 4-4 with hammer against Shawn Adams of Nova Scotia, the Ferbey Four
were sitting shot at the back of the eight foot with no other rocks in
play. Randy and fourth thrower David
Nedohin discussed their options. In this
situation, Randy and Dave guessed that Adams may not simply surrender a deuce,
but instead try a freeze, attempting to limit them to a single if successful,
at the risk of Team Ferbey scoring three points. One year earlier, they were two up in the
final end against another team from the Bluenose province, skipped by Mark
Dacey. Nova Scotia had beaten them with
a score of three in the final frame, thwarting the Alberta team's chances of
winning an unprecedented four Briers in a row.
That 2004 loss, combined with their confidence in David's ability to
draw the button on his final shot, led them to a very strange call. They took out their own rock.
My first reaction was, like many, shock. My next thought was “what would Bill James
think?”. Twenty years earlier, as a
pimpled teen running my own fantasy baseball league, I had stumbled across a
book called the Baseball Abstract. As he
did for many others, Bill James transformed the way I thought about baseball
and statistics. Before the 2005 Brier, I
had recently read Moneyball, the 2003
Michael Lewis book about Billy Beane, the Oakland Athletics, and
analytics. Reading Moneyball had jarred my memory of those Abstracts and the way Bill
challenged his readers to think differently about sports.
My next step was to search the internet and it led me right
to CurlingZone. I lived in Calgary at
the time, as did the website’s co-founder Dallas Bittle, who then introduced me
to Gerry Geurts. Dallas and Gerry were,
like me, disciples of Bill James. The
first release of their Black Book of Curling included new statistics (Hammer
Efficiency, Force Efficiency, Steal Efficiency and Steal Defense Efficiency)
and results from the 2004/05 Season.
CurlingZone had collected line scores of most every
meaningful game from previous years.
Lifting a concept from baseball, I took this data pool and created a Win
Expectancy chart. In baseball, you can
determine the odds of winning during each static position in a game. Based on the inning, score, number of outs
and runner(s) on base, a team will have an expected chance to win the
game. With curling, there were
limitations, but at least we could determine some chance of winning based on
the score and the number of ends remaining. The second edition of the Black Book of Curling in 2006
included articles from me and Gerry, using the results from these charts. Gerry
examined 1 up without hammer in the last end and I dove into the legendary
Ferbey take-out from the same 2005 Brier final that had launched the idea in
the first place.
Don “Buckets” Flemming was a sports writer from Edmonton who
focused on horse racing and curling after the Edmonton Flyers hockey team
folded in 1962. Don brought his interest
in numbers and math from the horse track to the rink. Shooting percentages and the 4-point system
were born. Larry Wood, then covering
curling for the Herald in Calgary, had devised a similar 3-point system around
the same time. Larry mentioned to me he
and Don used their own systems, and often had a similar result. They shared their ideas, with Larry bringing
the actual perspective of a curler and Don of a handicapper. Calculating shot percentages, Larry surmised,
was also a wonderful way to stay focused on the game and avoid tipping too many
beverages in the lounge.
On August 1st 2006, Don Flemming passed away. Over four decades after its creation, the four-point
system, still the standard for curling statistics, had out-lived its
founder. Dallas and Gerry attempted to
improve on its design and in the 2006 edition of the Black Book revealed Shot
Tracker Shooting Statistics. Built on a
similar point system, they added sweep factor and a degree of difficulty
modifier. Before, a team that played
conservative and attempted simple shots would have higher percentages than
those with a more aggressive strategy.
Now teams could be compared more closely, regardless of their own ice
strategy.
With Moneyball
released in 2003 and the Black Book in 2005 and 2006, you might imagine curling
went through a historic transformation, with teams clamoring for this new
information and adjusting their preparation and in-game strategy to align with
these findings. Not quite.
Canadian Curlers are generally a conservative bunch. Push brooms had been in existence for 100
years in Europe, but it took a long-haired junior with plaid pants to show
Canadians that the corn broom was a less effective device. Beginning with their early use in Calgary,
the full transition for Canadians from corn to push brooms took over a decade. The single sweeper technique unveiled in 2015
was available 40 years earlier, but curlers never figured it out. When the
world embraced the four-rock free guard zone in 1993, Canada held tight. A year later, we dipped our foot in with the three-rock
rule, and many older players still grumbled it wasn’t needed. Ten years later, Canada finally aligned with
the world and moved to four rocks. With the rich curling history of staying squarely
in the past, is it any surprise analytics would take some time to catch on?
The third release of the Black Book of Curling in 2007 would
be its last, but the work was just beginning.
Around this time, blogging under Curl With Math became my outlet to write a Bill James version of
curling analysis. The small group of
followers were loyal, but the dismal add revenue amounted to an extra cup of
coffee each season. In 2013 I released
an e-book, End Game: An Olympic Viewer’s
Guide to Curling, which was a collection of articles with additional
information (thanks if you paid for a copy).
Other than the realization 1 up (without hammer) was better than 1 down
(with) in the last end, only a few players took a passing interest. One exception, a young underdog skip at the Canada
Olympic Trials in 2009 by the name of Jason Gunnlaugson. You might have heard him spewing numbers on
mic over timeouts while playing fifth for Brendan Bottcher at the 2017 Olympic Trials,
or during a recent Grand Slam, referencing Kevin Koe’s success in the final end
when tied. His approach against Mike
McEwen in the 2018 Brier Wild Card game, leading to a narrow extra end loss,
was a prime example of great execution matched with a data derived strategy.
Gerry eventually built a presentation around these new statistics
and concepts, and evangelized with anyone who would listen. Scott Higgins of the USA High Performance
program had seen the Black Book and invited Gerry down in the summer of 2009. Though there was some mild interest, teams
rejected the analysis as a tool to compete. In some instances, the stats were
examined to identify why a team lost, rather than help them win. Gerry had the coaches support, but ultimately
the teams and their skips did not see much benefit. Several showed some interest in the reports
Gerry was generating, but did not demonstrably alter their approach to the game
or use as a tool to prepare for their opposition.
Following the 2010 Olympics, Gerry coached Matt Hames
(joined at lead by podcast legend Dean Gemmell) on their way to a 6-3 record
and play-offs at US Nationals. During
the event there were some numbers used in preparing for each opponent, and it
helped guide their play in the opening ends.
This was the first instance for Gerry of teams using the numbers to
prepare for opponents.
After 2010, Gerry continued to provide reports to the US
program, but it wasn’t until 2016 that he would again test the use of analytics
directly with a team. Jacqueline
Harrison had him assist with strategy for the 5-rock rule and determine where
they needed to improve. Ultimately,
Gerry helped them recognize the importance of planned aggression, particularly
against a stronger squad like Team Homan.
Team Harrison had (to date) their best season in 2016-17. It started with a win in the Tour Challenge
Tier 2 event, and a Quarterfinal appearance at the Canadian Open, including two
wins over Homan. Their best result was
in the 2017 Champions Cup. They faced
Team Hasselborg in the semifinal, a team Gerry had also started working with
around the same time. The Moneyball-Bowl
ended in a 7-2 win for the Swedes on their way to a 5-4 loss to Homan in the
finals.
The Present
Team Hasselborg retained Gerry’s services over this past season, leading
into the Olympics. Gerry provided scouting
reports with situational analysis for their competition, showing how teams
performed during various scoreboard situations (up 1 or down 2, etc.). Following their Olympic Gold medal, Sweden
coach Maria Prytz was quoted
on working with Gerry. “He is
incredibly skilled at tactics and numbers so he can look at different teams and
explain how they play in different modes. It has been worthwhile for me to
raise different scenarios for the team”.
Maria explained that when she and the team started working together,
they first looked at their own game plan, "Then we started thinking about how we could take another step in
tactics and start matching our game with the opponents,"
In the spring of 2017, Gerry provided reports to South Korea,
and that summer participated in a camp with six USA teams. When it came to analytics, Teams Sinclair and
McCormick seemed the most engaged with Team Shuster appearing less
interested. However, on a recent podcast
with Nate
Silver and Neil Paine of ESPN’s FiveThirtyEight, they mentioned
CurlingZone, with second Matt Hamilton sharing, “He [Gerry] sat us down at our summer camp and explained to us where we
sat [among] elite players at certain things, like with the hammer/without the
hammer, up by one with the hammer/down by one with the hammer … and it went on
for all of the potential scoring scenarios. And he gave us feedback [on] which
positions we could be better at, which ones we’re really good at, where we need
to keep doing what we’re doing. Then he gave us some info on other teams in
those same kind of numbers. … I’d be lying if I said that didn’t come into play
at all.”
Jamie Sinclair saw Hasselborg’s success and engaged Jason
Gunnlaugson to provide analytics consulting for her team. Using Gerry’s data and reports, Jason worked
with them prior to the women’s Worlds in North Bay. They narrowly lost a Bronze medal when Russia’s
Victoria Moiseeva took two in the final end, but her breakout victory at the
Players Championship in Toronto, and her
quotes on working with analytics, has opened more eyes to what using numbers
can do for a team.
Let’s be clear. I’m
not suggesting these teams studied a few statistics and then flipped a switch,
turning from also-rans into champions.
Analytics in sports is a guiding tool that can be leveraged for many
uses, but execution and performance are ultimately what determine the
outcome. Three-point shooting in the NBA
is now the norm, but Lebron James is still the best player and the Golden State
Warriors win with sound team defense and exceptional skill from some of the
most talented players in the league, not simply because they jack up shots from
beyond the arc.
Curling data currently available is limited to line scores (and
shooting percentages) and can be susceptible to error, based on results from
mismatched teams, or misinterpreted when putting too much emphasis on small
sample sizes. Teams can examine their
opponent’s tendencies and plan their attack.
For example, Sweden was very aggressive against Canada but very
conservative versus China. There is
always danger in drawing too much from inconclusive information however, and
ultimately Hasselborg’s strong play may have led to wins in both cases
regardless of their approach. But in a
game often decided by inches, every tool a team uses can help make a
difference.
Gerry and Jason found that the use of the statistics has
been a benefit to teams simply by forcing an open dialogue amongst the players
and improving pre-game planning. A team
can use this information to confirm what they are seeing from another team or
help highlight a hole in their game they may not have noticed. Essentially, they use it as a tool to talk
about themselves, their opponents, and how to approach the game. Data can provide a solid base for teams to
come to agreement on why they might make certain decisions, remove doubt during
a game and improve performance. Rather
than the second sitting in the hack questioning in her mind the skip's decisions,
she is focused on the shot, having already reviewed the team goals and strategy
in advance.
Second for Sweden Agnes Knochenhauer on their use of
analytics “Firstly, it always comes down
to how well we perform out there on the ice. But what we could see when we
started to work with the numbers was that our own performance in combination
with the statistics gave us confidence in certain scenarios and patience in
other. We’re using the statistics to put the four of us on the same path, so that
we all know how to take on each opponent. It gives us strength and courage as a
team. It also shows the importance of each and every shot, from lead to skip,
for us to be able to control the game. The numbers combined with our own
experiences of every opponent gives us a good discussion on how to approach
every team.” More from Agnes on how they approached Korea in the Gold
medal game “The stats played a major
part because we knew how to play them to put them in an uncomfortable
situation. We also knew what didn’t work since we lost to them in the round
robin getting trapped in their game plan. With stats from CurlingZone we knew
what type of game they had been playing all week with great success and it was
our job to break that and take advantage of the game.”
The idea of game planning in curling is less developed than
many might suspect. Traditionally, skips
ruled their teams like a drill sergeant and players were rarely asked for their
opinion. Years ago, pre-game warm-up might
be held in the lounge with a brief chat over a cold beverage. Teams have begun to spend time on preparing,
but it can be dangerous to say, “we’re going to be a more aggressive team”
without looking at data to understand how aggressive and in what
situation. Gerry noticed one team that
had great statistics when playing without hammer but in attempting to become
more aggressive with last rock, their defensive play suffered and they dropped
in the rankings as a result. The
application of strategic adjustments based on opponents is still in its infancy
but these results this past season show what is possible. Curling is often called chess on ice. I doubt there are many grandmasters who use
the same opening moves in every match.
In football, a team builds a game plan during the week from watching film
and studying their opponent. Why would
curlers want to step on the ice expecting to play the same way every time?
Rachel Homan’s coach Adam Kingsbury recognizes the benefits
of analytics. Like Gerry, he believes it
can benefit a team many ways, like reinforcing team principles on strategy, or
recognizing your own strengths and weaknesses.
Team Homan was not surprised that their opponents took an overly
aggressive strategy in PyeongChang. They
were prepared for the onslaught of guards, freezes and come-arounds faced. Rachel generally has a consistent strategy
against all opponents, usually forcing their style of play rather than adapting
to their opponent. The challenge is when
you don’t execute to your expected level, the other team can start to dictate
the style of play. Adam suggested this
was the case in the Olympics, with the difference coming down to perhaps five
critical moments that swung the difference in qualifying for the medal round.
It was through Adam that I heard about funding from Canadian
Tire to assist Curling Canada in an analytics project. When we discussed this in spring of 2017, we
were all excited by the potential to move curling analytics forward. From what I understand, it appears more work
needs to be done. I’ve not seen what’s
been built, but Adam described it as the same information that was generated
from those Win Expectancy charts back in 2005, but with better graphics. Perhaps this is only Phase 1 of the project,
and maybe they’ve built a potential analytics engine that will add value as it
evolves. Understanding the funding model
from Own the Podium and the delicate position of being responsible for Canadian
teams, I respect why our governing body finds it necessary to keep the
development a secret and limit those who have access. Imagine if Glenn Howard had used the system to
gather data on our teams ahead of coaching in the Olympics for Team
Muirhead? Sadly, it is this restrictive
nature that limits the adoption of this analytics initiative. Holding onto this information until it’s
revealed to the Trials winners two months before the Olympics ensured it would
only be a minor novelty. A competitive
team, particularly those who’ve excelled at the game without using analytics, is
not going to introduce some new concept eight weeks before the most important
event of their lives. I believe Curling
Canada could have benefitted from engaging more outsiders in the original
inception, including players and coaches to help develop something more
valuable that would have become ingrained in a team’s preparation. I’m also a realist and this would likely have
taken too much time, grown the scope beyond what the budget allowed, and as
mentioned risked the scrutiny of those who are paying to protect Canada’s medal
count.
In his early days, Bill James had battles with the Elias
Sports Bureau. They refused to provide
him with detailed major league baseball data, claiming it was proprietary. In the end, Bill developed a volunteer army
called Project Scoresheet to collect
what was needed to progress the analytics movement forward. Elias had their reasons for withholding
information. They are a corporation and
making money is one of the essential pieces to running a successful company. Curling Canada won’t dramatically alter their
position in the future, so innovation may have to come from other sources.
The Future
When progress happens we often regret how far we are to the
finish, until we stop and look back on how far we’ve come. There are now several players and coaches
quoting on their use of analytics in preparation this past season. Those of us toiling in the data for over a
decade may be dismayed we still only have basic information, but acceptance is
the first step. No doubt there will be
greater opportunities in the coming cycles to push the possibilities.
In 2012 I submitted an idea for a curling paper to the MIT Sloan Sports Analytics conference. It got rejected. In 2013, I tried again. This time they agreed and, with help from
Gerry I submitted a paper which, among other concepts, examined the even ends
theory. It got rejected. Now that Shuster has a gold medal, perhaps next year curling may finally get its opportunity to join the conference.
Coaches, teams and even countries are starting to ask Gerry
and Jason for more information and how to get started. Others are likely to expand their past
efforts or join the fray. As mentioned, Curling
Canada could develop a next phase of its analytics program, and other countries
are sure to invest as well. Andrew Denny
has been writing analytics articles for The Curling News the last few years but
perhaps now he’ll have a chance to bring his ideas from newsprint to the ice. Mike Bowling and his team at the University
of Alberta have been working on an Artificial Intelligence program
for curling, but have lacked the required data and interest. Perhaps with Shuster’s success and the new focus
on analytics, we could see a renewed investment (perhaps with help from Google’s
DeepMind) to accelerate their work.
There is more analysis that can be done even with the data available
today. Shooting percentages could be
examined further with the ability to link results to the outcomes. Grouping similar teams and factoring strength
of opponents with the data is another next step. The real opportunity, however, will come when
we have a data pool full of shot information.
Eventually we will be able to collect every shot, it’s direction, speed,
rotation, eventual location, linked to each game and situation. We’ll be able to determine what Brad Jacobs’
scoring chances are when there are 2 guards and 1 opponent rock above the tee
line in a tied game. Brandon Corbett has
developed a camera system that can track curling rocks
within ¼ inch. As a training aid for the
delivery it’s phenomenal, but with a little more development and funding to
implement at major events, this system could record everything that happens on
the ice, like Second
Spectrum does for the NBA today. In
the meantime, perhaps a Bill James Project Scoresheet for curling would be
possible. CurlingGeek has data available
on rock locations, as does the World Curling Federation for many of the major
events. Video libraries exist that could
be mined for more information, and perhaps Curling Canada would even share its
data as well. I understand that several
coaches share some information today, such as rock sequence to reduce the
effort of having a scout with binoculars in the stands. It’s information that is open to the public and available to all, but just needs
to be logged. Could we do the same to
record every shot? If there was one
application that coaches used to input shot data from their games, would they
want to share it in order to get everyone else’s data? I’m skeptical, but there might be a chance.
The fear today is the data is too valuable and must be kept
secret. Nothing could be further from
the truth. At this early stage for
curling, the path to greater insight and adoption will only come when
information is shared. The way to create
and collect the large data pool we need to advance analytics is to have
interested parties with the required skills and background working
together. The competitive advantage is
not the data itself, but from its analysis and how it is put to use on the
ice. A quote from the 2018 MIT Sloan Sports Analytics Conference
“The toughest thing about analytics is
not the math, it’s figuring out the right question to ask”. In curling today, we have so many
questions. We only lack the data to
answer them.