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The use of technology and AI in curling
The header image for this post is a photograph of Randy Park, a practicing engineer from Hamilton, and Randy’s portable rock-throwing robot, called SweepTracker, which he constructed himself in order to conduct research on the forces involved in curling and, more specifically, the changes to those forces when a stone was brushed. In this IEEE Spectrum article by freelance journalist Elie Dolgin, Elie takes a look at some of the technologies now being used in the sport of curling. My own conversation with Elie included such things as smart glasses for weight judgment in brushing, instrumented brushes, artificial intelligence and machine learning, robotics, and analytics. Myself, Sean Maw of the University of Saskatchewan, Curling Canada’s Mick Lizmore from London, and Emily Zacharias of Winnipeg were just a few of the researchers from around the globe that Elie interviewed for this article. It’s a really good read.Â
Calibrating the CurlSmart instrumented brush
Frequently, the athletes that I work with on brushing – over 550 since the 2014-2015 season – complain about the CurlSmart instrumented brush for two reasons: it’s, well, heavy. Including the 9V lithium battery, the CurlSmart brush head weighs 534 g, somewhere between 2x and 3x the typical weight of a commercial brush head due to its steel plate construction. The black Cordura nylon fabric on the brush head, which we use for its durability, doesn’t have nearly the same “feel” as a World Curling-approved brush head. Cordura nylon is used on the CurlSmart brush because replacing the fabric on the brush head is a fairly involved procedure that requires disassembling the head, stapling in the new fabric, and reassembling. Moreover, replacing the fabric usually merits a subsequent calibration test of the brush to ensure that the procedure did not impact the brush’s accuracy. Nevertheless, we chose to replace the black Cordura nylon with SportLite+ fabric from Balance Plus in
The physics of curling – with Sean Maw, University of Saskatchewan
This past week, my friend and research colleague Sean Maw, who is the Jerry G. Huff Chair in Innovative Teaching and an Associate Professor in the Ron and Jane Graham School of Professional Development, Division of Biomedical Engineering at the University of Saskatchewan, was interviewed by Matt Olson for the University of Saskatchewan’s Signature Series podcasts. In the interview, Sean outlines a number of research problems with respect to the physics of curling and our short-term research goals for the near future. There remains a considerable amount of work before we come to a more complete understanding of the physics of curling, including the impact of brushing. You can listen to the complete interview by clicking on the introduction at left, or you can listen to the podcast on Apple podcasts (and others) by searching for the University of Saskatchewan Signature Series podcasts. Â
A Case Study with Scoring Metrics
A look at the 2025 OUA Women’s University Curling Championships In my previous article I outlined some basic curling scoring metrics, namely hammer efficiency, steal defence, steal efficiency, and force efficiency, and how they are computed for any particular team in a specific event. These four measures are routinely reported in the Curl Coach app and in Curling Zone event results. According to Curling Zone’s Gerry Geurts, the hammer efficiency metric was based on an idea first proposed by former Canadian champion and Olympian Linda Moore, who proposed that what percentage of time a team with last rock was actually able to score two points was a good measure of a team’s ability. Gerry, along with colleague Dallas Bittle, took that idea one step further and created the other metrics along similar lines. Subsequently, Hammer Factor, Without Hammer Factor, and a Combined Team Index were proposed that simply combined two or more of these elementary metrics.  In this article, I’m
Hammer efficiency, steal defence, and other metrics
In addition to player and team shooting statistics, which are often displayed on curling TV telecasts, another set of statistics common to curling are scoring metrics that summarize a team’s ability to capitalize on last rock advantage, steal points in ends where they don’t have last rock, and their ability to defend against team(s) when the opposition has last rock. These are relatively rudimentary performance metrics, but they can offer some insight to a team’s performance. If one is using the Curl Coach app to chart games those summary scoring metrics are shown on the main Competition page within the app – regrettably these statistics are not duplicated in the generated Competition Report PDF. An example of these statistics captured with Curl Coach appears at right. In addition to the base statistics shown for this competition: number of games played, wins and losses, average points scored for/against, etc. there are a number of additional metrics, such as Hammer Efficiency (called
Why bunny-hop brushing may not be the advantage you think it is
Increasingly, this season I’m witnessing the adoption by Canadian Junior and U18 teams of a brushing tactic used by some teams – mostly, but not exclusively, women’s teams – on the Grand Slam circuit. I’ve nicknamed that tactic “bunny-hop” brushing as it involves the near brusher jumping during the “push” portion of each stroke from a snowplough position. Most often I see the bunny-hop used on guards and draw-weight shots, where the tactic is employed between the far hog line and where the stone comes to rest. Typically, the bunny-hop is used when the stone requires additional carry, though sometimes the tactic is also used when trying to both extend the carry of a stone and, at the same time, accentuate curl by brushing in the direction of the stone’s rotation. https://youtu.be/o2woYB05zdU?&t=1843 Carole Howald of Team Tirinzoni uses the “bunny-hop” brushing tactic vs Team Homan in the final of the 2025 AMJ Campbell Players’ Championship. Rationale The idea behind the