Blog
A preliminary investigation into knifing
On the afternoon of February 19, 2026 I met with Sean Maw and his research team from the University of Saskatchewan, along with Rob Gordon from World Curling, at the Nutana Curling Club in Saskatoon, SK to conduct some preliminary work into the brushing tactic of knifing, and to continue a profiling survey of a selection of Nutana’s curling stones. Curling stone profiling One of the many variables to be considered when doing on-ice testing of curling equipment – particularly brushes – is the characteristics of the curling stones being used in the tests: both mass and the roughness of their running bands. Mass is trivial to measure with a standard weigh scale; but having a quantitative measure of a stone’s running band requires a surface roughness profilometer, such as the Mitutoyo SJ-410. The video at right illustrates the output of the SJ-410 on a single path across a curling stone’s running band. https://youtu.be/2dFJ8JxPm_g To produce a profile of a
Delivery analysis clinic – Guelph Curling Club – 15 March 2026
Throwing Rocks Consulting Services Ltd plans to offer a delivery analysis clinic at the Guelph Curling Club on Sunday, March 15 2026 between 6:15pm and 8:15pm. The Guelph Curling Club is located at 816 Woolwich Street in Guelph, Ontario. In addition to an introduction (or review) of delivery analysis fundamentals, participants will gain experience with a delivery analysis setup and its equipment, and with using OnForm’s multi-camera analysis tools with which to analyze a curling delivery. Cost for the clinic is $40. This clinic is targeted towards coaches who work with competitive U15, U18, U20, or adult teams; it is not intended for instructors who work with little rocks or novices to the sport. Participation is limited to 12 coaches and will run only if at least 8 coaches have signed up. To secure your spot, the $40 fee must be paid in advance of the clinic. The fee will be reimbursed if the clinic is cancelled. Additional participants will
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