Dr. Glenn & Coach Bill Talk About Brushing

This episode of "A Pane In The Glass Podcast" started with an email from me to my friend Dr. Glenn Paulley about this new brushing phenomenon called "The Bunny Hop". Glenn's reply led to an invitation to join me on the podcast so you could hear his thoughts directly and let's just say, regarding this new brushing technique, were surprising. That led to a discussion about a number of other aspects of brushing resulting in this information packed episode. In the introduction to the episode I list the topics about to be aired and there were many. This is one episode, if you are a coach or athlete, you might want to make some notes. The transcript of the episode will make a good reference to the discourse between Dr. Paulley and yours truly!

Transcript

Speaker 0:18

Welcome to another episode of the Pane in the Glass Podcast. This is your host, Bill Tschirhart chartered profesional coach with Coaches of Canada, along with my friend, Dr. Glenn Polly, who doesn't live very far away, who is one of the world's leading researchers on the science of brushing. And Glenn has been on episodes with me in the past talking about that subject. And I know that most of you out there who are regular listeners to the podcast, and thank you very much for doing that, when there is brushing on the menu, the number of downloads, well, to say it spikes, would be putting it mildly. And these are some of the things that we're going to talk about today. But before I list those topics, if you are an elite curler and you are one of those teams that play on television at slams or national championships, world championships, and Olympic Games, you might want to pay attention to what Glenn said. So I'm not going to bury the lead here. Some of what you're doing isn't supported by the sport science. I'll just leave it at that. So here's what we're going to talk about in no particular order. The bunny hop, and we're seeing that technique more and more with some of our top teams. I'll just leave it at that. Throughout the episode we talk about feet and hips. That your feet as much as possible need to be outside the hip line, and Glenn will explain why that is so important. Stroke rate versus downward pressure, which is more impactful? Two brushers versus one, which is better? Footwear, grippers on both feet, or gripper and slider. Snow plowing for the first portion of the rock's path, or as doctor Glenn calls it, planking before you start brushing. We talk about visually recording, not just brushing, but also how to do it with a delivery. And again, on the journey that the rock makes down the ice, is the brushing going to be more impactful in the first part of the journey of the rock or near the end? I think you'll find that very interesting. And then the number of rotations. So we're definitely seeing teams now applying more rotations than perhaps we have in the past, and then we'll give you the reason why. Here we go. Glenn and Bill talk about brushing. Well Glenn, it's been quite the passage of time over the past number of years. Brushing has certainly come to the forefront on a number of levels. I thought that, well, the fabric that's being used is important. And then, of course, this thing about foam density. Who knew that we were going to get involved with those aspects of brushing? And of course, everything that we see on television, we're seeing different techniques. So I thought, okay, I'm easily tricked. I'm going to go to the one person that I know who knows what they're talking about and won't try to trick me. And that's you, Glenn. So tell me how you feel about what you see with brushing.

Speaker 1 4:04

So it's been, yes, it has been certainly uh an interesting last couple of years, and it's been a very interesting season this year. There's there's still a lot, there's a lot that we know. We're in a much better situation about understanding what's going on with brushing than we were five years ago, for example. But there's also a lot of things that we still don't know and still require investigation. And one of the things that we need to do, I think, as a sport to move forward is not only to have a better understanding of the physics of what's going on, so that we can be in a better position to regulate the sport and potentially redefine the rules behind the game, but also uh come up with a better specification for brushing devices so that we avoid situations like foam gate and broom gate that have happened in the last 10 years.

Speaker 4:59

The mustard yellow fabric that now is uh the compliant material. I love that word. It's the compliant material was selected from a variety of fabrics back in Kempville, Ontario, during that summer. And it seemed like this particular fabric was the best compromise, I suppose, from actually affecting the pebble and not uh damaging the surface. Because there actually is a rule that uh you can't use anything that touches the ice, it's going to damage the surface. And so that certainly was the primary reason that it was successful. And the term that certainly comes to my mind from a person who I know was there was that we're back to polishing the ice, we're no longer uh laying tracks and uh and cutting cutting the pebble. And it's been interesting because when I get into an environment where we have some of our top ice technicians, the almost the very first question I asked them since the yellow stuff, the compliant material uh was adopted, I go to them and say, is there any evidence from your perspective that the ice is being scratched? To a person, the answer is nope. No evidence from my perspective that the ice is being scratched in comparison to what was happening before uh the study that was conducted in Campville.

Speaker 1 6:34

Right.

Speaker 6:35

Well, some things have happened recently, and it caused me to send an email to you. Uh, one was about uh the bunny hop. Um, I think uh Carol Howell from uh Team Tier and Zony was the one that she might not have uh uh developed it, but she certainly was uh the poster uh woman for the bunny hop. And so tell us what you think about that technique.

Speaker 1 7:04

I think that the idea behind athletes using the bunny hop is to try to increase the amount of vertical force that's applied to the broom at the beginning of the push portion of the stroke. In normal brushing, when you have your feet on the ice, it's it's exceedingly difficult to produce an amount of force down the handle of the brush that's greater than your body mass. So a top player when they're brushing, so uh, you know, a top male player who plays at the briar will typically produce a maximal force at the beginning of the push portion of the stroke of somewhere between 80 to 95 percent of their body mass. So if you have a player who weighs 100 kilograms, then at the beginning of their stroke they're gonna put 95 kilograms of force down the handle if they're if their technique is good and they're they're a good athlete. For women, it's a little less than that. The only way to get a higher amount of force down the handle of the broom that's greater than your body mass is you have to drive the broom into the ice. So you can either lift the broom with your hands and drive it into the ice like a pile driver, or you can jump into the air and then using gravity as you come down, increase the amount of force down the handle. I think the I think the purpose behind the bunny hop is to try to maximize that amount of vertical force on the on the push portion of the stroke so that it's greater than what the athlete could achieve using a more traditional brushing technique with both of their feet on the ice. How much a player can do that depends on a number of things. It depends on their athleticism, it depends on how high, how high they can get their feet off the ice. It depends on the angle of the of the of the broom handle. It depends on a variety of different factors, but it's almost certainly going to lead to a couple of counterproductive things. So one of those things is that it's very difficult to move in the human body, very difficult to move large muscles quickly. Usually what ends up happening if if a player adopts the the bunny hop, they have to time their jumps to their strokes. Because if they don't do that, then it then the technique is completely counterproductive. So they have to be able to, as they're coming down from the jump, push the broom away from their feet. So they have to time their jumps with their strokes. So because they're jumping and they're using the large muscles in their legs in order to be able to do that, their stroke rate will go down. And usually when players employ the bunny hop, it's at the end of the shot, often starting at say a zone two position on the sheet. So just in front of the just in front of the house. So the player is trying to get the the maximal amount of additional carry that they can as the stone is going into the rings. And and that's the most important time to be as technically perfect as one can be to maximize the amount of force going into the ice, and at the same time to make sure that you're overlapping your strokes as much as possible in order to raise the ice temperature, because we know that the carry of a stone is proportional to how much you can raise the temperature of the ice. But if you're using the hop, you're slowing your stroke rate. Almost certainly slowing your stroke rate because you have to match your stroke rate now to how frequently you can hop. So the larger the hop, the slower the stroke. If you want to speed that up and you want to still try to maintain a uh a high frequency of strokes, then your hops have to be very short and very small. And usually when you do that, your feet have to be directly underneath your body. And the problem with that is that if your feet are underneath your body, then your body mass is now on your feet instead of being on the broom. And so you're actually having less force on the broom than you would if you simply adopted the normal brushing stance. So that's another problem. So it takes, and and and to your listeners, I would say that it takes it takes a very, very significant amount of athleticism to be able to do that stroke and jump in the air and keep your feet behind you so that when you come down, your body mass is still over top of the brush end. And then the third problem is that as Newton's Newton's paraphrase of Newton's laws of motion, what goes up must come down, the athlete now has to get ready for the next jump and they have to jump in the air in order to be able to do that hop. And when they jump in the air, chances are they're going to either be uh putting zero amount of force on the brush head, or they're actually going to be lifting it off the ice. That amount of lift off the ice may be imperceptible to the athlete, but it's certainly measurable. And and I've done an experiment with with a player on my team that illustrates that. So in effect, what you get is you do get, you can get a slightly higher force value with the push portion of the stroke. But at the end of the stroke, you either have a very small amount of force over top of the brush head, or the force is actually negative because you're lifting it off the ice. And if you average those two things, then your average force that you're developing through that stroke is actually less than if you're using the more traditional technique in the first place.

Speaker 13:01

Gripper, gripper versus gripper slider.

Speaker 1 13:06

So most players that I've seen use this use double grippers. There are a few who who do it with the slider. But with a slider, usually what I see happening with the athlete is because they're using the slider and they're gliding on the slider as they're going down the sheet, the slider is in fact directly underneath their hip. So robbing that body mass being over the brushhead in the first place. The second problem that I see, and and I've I've seen this uh doing experiments, in fact, saw this in in uh Saskatoon last month uh when we were doing some testing. Is if you if you adopt that technique with a slider, every time that you come down on the ice with that slider, you're marring the ice. You're your ice is very brittle and you're you can crush the pebble every time you jump on the ice with that slider. And you can see the marks in the ice after after one sweep. It's it's plainly evident that it's there. So that's another factor that I think a lot of of a lot of players don't think about when they do that.

Speaker 14:10

The sort of age-old question about stroke rate versus pressure. I know that there's a bit of a back and forth on this over time, but given current circumstances with brushing, where do the two comparisons, the comparison of the two, where does that settled in at this time?

Speaker 1 14:34

Heat, the transfer of heat from the brush head into the ice has been studied for at least 20 years now, if not 25. We know that uh lowering the coefficient of friction on the ice by increasing uh the ice temperature marginally through sweeping is uh a component of both things. So one is pressure, which increases the amount of friction that's applied into the into the ice surface, and the other is being able to brush a particular piece of ice more than once. So depending on your angle of attack um behind the stone and the type of stroke that you're using and the orientation of the brushhead uh as well, you you can apply more force with proper biomechanics. But there's no question that increasing your stroke rate is also going to assist in uh raising the ice temperature and increasing carry for sure. What I do in my coaching, I concentrate on force generation first, making sure that the athlete has the proper biomechanics in order to be able to produce as much force on the brush handle as possible. And then once they are able to master that position, then we can work on speed. So we know from studies that we've done, including the uh currently Canada Brushing Summit that was done in 2022 in Morris, that there's a positive correlation between carry distance and mean force on the broom. So irrespective of stroke rate. Now, that said, it's interesting to me, based on all the data that I have, of how how little variance there there is actually in the stroke rates, certainly of players in Canada. The typic the typically the Asian teams frequently brush with slightly uh stronger higher stroke rates, but also from their biomechanics, it's plain that they're they're not putting as much force on the brush head as uh as what we tend to see here in Canada. So typically the Asian players almost all of them brush with sliders, almost all of them brush with their feet underneath their hips. And so when when there's less force on the broom, it's easier to have a higher stroke rate. But even though their stroke rate is higher, it's not appreciably higher than what you see from from Canadian teams. You know, a top Canadian player will apply, as I as I mentioned earlier, you know, 95% of their of their body mass on them on the brush during the push portion of the stroke, but they'll still brush at a stroke rate of five strokes a second. From the Asian teams, we're seeing stroke rates probably at six strokes a second, perhaps six and a half strokes a second, but with predominantly less force. Um, not that I've measure them because I only work with Canadian teams.

Speaker 17:50

On to a slightly different topic, although I think it's related based on the discussion that we've had thus far, for mere mortals playing in a competitive league in one's curling center, where the W's and L's make a difference. So although the team doesn't practice very often, uh they do want to maximize their performance. And of course, part of that maximizing of performance is to brush as effectively and impactfully as possible. And so, in the initial email that I sent to you, it seemed that there might be a way to maximize the brushing and the impact that the brushing has with a uh recreational team if it was virtually out of the question to quote unquote hurry hard or go hard right out of the uh the person's hand and go hard all the way to the uh termination of the rock itself, that they might go hard for say 25% of the journey, maybe 35%, but from there on they're flagging. And so it seemed that uh technique that we're seeing now is that uh I hate the word I'm going to use, snow plowing, but everybody knows what that means, of course, that you don't move the head of the brush, you just use your body weight as much as possible, hopefully with feet outside the hip line, because that technique is important. And get to that point in the rock's journey that now my brushing partner and I, we have the physical capacity to go hard the rest of the way. But that that combination probably would help getting the rock further down the ice than if we the traditional hurry hard right out of the player's hand. So perhaps you could speak to that.

Speaker 1 19:57

Even on keen ice at draw weight, a stone is moving at at least two meters a second. On really good ice, it's it's moving slightly slower than that because it's still going to make it to the far end. But I would say it on club ice, a stone is moving around 2.2 meters a second at release. Well, that's around seven feet in a second. If your stroke rate, which is typical, is around four strokes a second. What you're trying to do is you're trying to sweep the ice in front of the rock with four strokes in the same second that it's moving about seven feet or two meters, maybe a little more than two meters. If you're brushing from the side, you're not going to cover all of the all of the ice in front of the stone's running band, if you're brushing from the side, because you're going to zigzag in front of the running band. If it's a draw shot, then brushing from behind the stone makes a lot of sense because now your broom is in front of the running band through the entire process. If your technique is solid and you can keep your feet behind your hip line and you can, you know, get your upper body over top of the brush. If you're if you're in a snowplow, as you said, plank position from behind the stone, what what I've measured with many teams is that they're able to produce approximately the same amount of mean force, just being in that plank position with no brushing motion as if they were actually brushing the rock in the first place. They can so they can they just by holding the broom in front of the rock, they can still achieve their mean force. What they're so they can achieve the mean force without resorting to the additional exertion of actually doing the sweeping motion. The thing that they're missing, though, out of that process is that they're not getting the benefit of overlapping strokes. So they're not raising the ice temperature as much as if they were actually doing the brushing because we're not seeing the overlapping strokes any longer.

Speaker 21:55

Well, then just just if you don't mind, let me just interrupt. So often when I'm watching brushes on television and they're trying to oh I don't know exactly how to express this they're not trying to do anything fancy that's not a very good way to express it anyway what I'm saying is why are they both not brushing?

Speaker 1 22:17

I mean if we want overlapping strokes why is one guy just you know being a cheerleader so over okay so that's a so that's a great question and I get asked that all the time we know from studies my colleague John Newhook has done a study in Nova Scotia I have a study from World Curling as well that two brushers are better than one two brushers are better for carry two brushers are better for holding a stone and that's true for junior players it's true for adult players it's true for players on the on the world curling tour but with the players that you watch on TV regularly the the players who play at the Grand Slam the players who play at the Briar the the players who play at the at the at the Scotties although this is less true for women because there is a force profile component to what it is that you can do with the rock with the shot tolerance that they have and the keenness of the ice that they're playing on and the athleticism of the athletes they've determined that they can get away with one brusher for the most part. You will see men, even men's teams, you will see them resort to two brushers when it's absolutely necessary and you do see this all the time. I wish that some of the teams would practice brushing with two players more often than I think they do. And you can certainly use just a single brusher as an energy saving component for your team. So this is what I this is what I do with my women's team my U25 women's team like we're in a situation where usually the events that we play in are on weekends. So the event will start on a Thursday or or on a Friday and you'll play seven games in a weekend or eight games in a weekend and often three games on championship Sunday. If you're gonna brush every draw shot and you're gonna brush it from stem to stern with two people you're gonna get pretty tired by the time you get to championship Sunday. So as an energy saving tool what my team does is we'll only use one brusher for hits that are above board weight. And we'll use two brushers for every shot that's lighter than that. And then again at the beginning we'll often do the snowplow at the beginning of the shot because brushing is less effective when the rock is moving more quickly and it's more effective when the rock is moving more slowly. And so we'll snowplow for the first half of the shot, especially if it's a draw or a guard, and then determine after that okay so now given the speed of the stone and the uh intended resting place for the rock in the rings or in front of the house, how much brushing do we need to do in order to get it there? And then we'll use two brushers if that's required.

Speaker 25:00

I'm going to ask a physics question. My participant observation that's my favorite phrase Glenn my participant observation my participant observation is that when a stone comes to the conclusion of its journey I'm trying to choose my words carefully here that two things appear to happen at the same time. And I think you know what those two things are I'm pretty sure I do yeah it stops rotating and it stops moving forward. Yes now the question is is one antecedent is does does does the stone stop moving forward because the rock stops rotating or vice versa what's your take on what you're saying is in a nutshell a an explanation as to why curling stones behave differently depending on how much rotation that you throw.

Speaker 1 26:05

Yes right and how much rot and and how much rotation you throw impacts the amount of curl that you're gonna see at the beginning of the shot which also is related to the roughness of the stone's running bands. So running bands that are very rough are going to require more rotation in order to behave I hesitate to use the word properly because that's not what I mean but you're gonna require more rotation with roughened running band stones than you are if the running bands were smooth. And if you apply less than adequate rotation then the stone will begin to dig in and as soon as that happens then the weight is going to come off the stone entirely and your shot will stop short.

Speaker 26:55

One of the things I say to brushers when they're flagging on a on a draw shot that hey boys and girls is if the handle's still turning it's still moving so if you if you want a little bit of Newt Rockney here okay watch the handle.

Speaker 1 27:14

Okay keep brushing and because when the handle stops well forget it because the rock has also stopped right I mean so so one of the things that curling canada has now put into the the coaching courses for delivery is to have players throw with a greater amount of rotation than what ordinarily we'd we would have done 10 years ago. And the reason for that is because if there's more rotation on the stone say somewhere between four and five rotations between the hog lines then the stone is much more easily managed by the players in terms of of brushing because the stone with that amount of rotation the stone is not going to dig in nearly as often as it would if you only threw two rotations between the hog lines. And so you're gonna get much greater shot consistency. And then the other reason for doing that is especially for competitive players when they move into an arena ice situation and they play with very sharpened stones, it's less of an adjustment for the players to make to go from throwing with five rotations hog to hog to six rotations hog to hog than it would be on their release if they only threw two and now all of a sudden are completely bamboozled by the ice in the arena and now have to throw five or six in order to make a shot.

Speaker 28:33

Another aspect of brushing and then if I'm working with that uh team that's in a recreational environment but they want to play as well as they possibly can and we get to talking about brushing from a technique perspective I say how often do you record visually record your brushing and the answer I get most of the time is crickets. They they'll I I've got them I've got them recording their deliveries so that what they think they're doing they're actually doing and they're really like they really like that then I say that question like how often do you record your brushing and they never do and I say well how do you know what you think you're doing with brushing you're actually doing so I hope that you would uh concur that teams need to record their brushing in practice sessions as much oh absolutely I could not I could not agree more strongly with what with what you just said it's we are just we are just now as coaches scratching the surface of what it is that we can do in coaching with video.

Speaker 1 29:43

All too often what I see teams do is they'll is they'll they'll run a practice and frequently teams don't practice brushing um which is something that you know also I would encourage coaches to do. But nothing beats video in terms of athlete feedback. And honestly the first thing I would do when working with the team is is take out my phone or take out my iPad and record the team brushing from the far end because it doesn't matter how good your technique is if you're not brushing in front of the running band you're not doing you're not doing any good whatsoever.

Speaker 30:24

Hello hello and it's yeah and it's it's well perhaps not surprising to you but it's it's eye-opening often for the athletes to show them those videos and show you know for a 14 second sweep how little of it was in fact in front of the rock especially if that player is the second brusher just talking about video again when an athlete comes to me and and there was a a a woman from Port Huron Michigan uh who uh contacted me and we would meet at the Sarnia Golf and Country Club one of the great curling facilities not just in the province but I think in the curling world I said to Stephanie I said Stephanie I'm gonna record your your delivery the first time we met and she said oh good you're gonna you're gonna analyze my delivery I said no I said I was going to record your delivery you're going to do the analyzing I did I recorded the delivery front side back and when I played it back I said now here's the deal I want you to tell me what surprises you you might be surprised with what you expected to see and didn't or that you saw something that you did not want to see and so often now I'm not talking about someone in a learn to curl environment I'm talking about a you know highly competitive and competent curler. And I know I know I know Stephanie so I know exactly oh yes I do yeah and I and I and I and I said to her that's all I want to know I want to know what surprises you and nine times out of ten they completely analyze their delivery and they'll turn to me and say Bill that was great I can't thank you enough yeah I held the the iPad I pressed record and stop that's what I helped you with. Yeah but it's but so often that's exactly the point make sure what you think you're doing you're actually doing and only then do I weigh in if it looks as though there's a bit of confusion between what the athlete is seeing and what they hope they would see or not see. So I I we're a little bit off topic here but over to you on that.

Speaker 1 32:42

But but it you know it's true for delivery but it's equally true for brushing. I can't tell you how many times I've worked with a junior team and not only do the players struggle with keeping their brooms in front of the rock and again especially if they're the second brusher because they lack because they're further away from the stone they lack that frame of reference for where their brush head should be. But the other thing is is that amongst the four players of the team if you ask them to brush a stone to achieve a particular effect out of the four players you'll have three different techniques for what they're trying to do. And so you when you record those and you say okay so Joey you tried to make the stone uh not curl and this was your angle of attack and this is what you were doing with your brush. And Adam, you were trying to do the same thing but this is your angle of attack and this is what you're trying to do with your brush and then Bill over here is you know got a third way of doing it. I think we could all agree on exactly how it is that we should be doing this.

Speaker 33:43

Well Bill probably knew what he was doing. Well maybe maybe not why but at least he had an idea. Yeah. Okay well Glenn we could spend the entire day here talking about rushing but those were the the what bubble to the surface with me of late and so uh again uh I can't thank you enough when when I got the responses through the email and I went through the material that you sent me and again thank you very much for doing that I thought oh no no we Glenn and I have to do this on Zoom because I want to hear Glenn's voice and we all do so Glenn I I can't thank you enough. Oh you're welcome you're very welcome wow I hope you would have the same uh impression much to unpack here I have gone through the episode as I prepare for the publication of the episode I've gone through it uh more than I've gone through any other episode and not just in the editing process uh taking out all the ooms and oas most of them on my part but just to wrap my head around what Dr. Glenn has said he is one of the world's premier researchers in the area of brushing along with Dr. John Newhook and Dr. Michelle Ladesser and Sean Ma at the University of Saskatchewan I believe I've got that right so these folks know what they're talking about and I I'm not going to bury the lead here Glenn and I have had this discussion before that when we see brushing on television brushing uh from the the perspective of the the very best teams in the world we sometimes shake our head when what we see is not supported by the sport science the sport science as the researchers know it. Now research might bring new perspectives but given the present research I'll be very honest with you some of the brushing that you see just doesn't support it. I know I catch myself saying a lot of times when a rock is brushed into the house into its final position and I say to myself if those two brushers had gone for a drink of water and not brushed it at all that rock was going to end up in exactly the same place. Some of the brushing just isn't very impactful. As far as the bunny hopping was concerned that there were definite advantages and Glenn enumerated those advantages but when you subtract the trade-offs the net result is kind of back to zero that really kind of jumped off the uh the podcast to me and I think about the number of times that between the two of us we mentioned how important it is to keep your feet outside the hip line and then stroke rate versus downward pressure downward pressure seems to win that battle but it is always something of a marriage between the two and Dr. Polly talked about the number of stroke rates but downward pressure still seems to be more important and then the whole two brushers versus one and again I see that all the time on television and I'm wondering why one of them is just a cheerleader when they should both be brushing. Now Glenn made a very good case for his U25 Next Generation team that when they go to a bond spiel starting on a Thursday through to Sunday sometimes for some shots using just one brusher makes very good sense. And then we've talked about this before in the podcast grippers on both feet or gripper on one foot slider on the other well there's five good reasons for having a gripper on each foot and I'll enumerate them very quickly once again you've heard them before from me first of all it's just simply safer and as one ages I say that with tongue in cheek um staying safe is probably a little bit more important perhaps than than thinking about it when you were younger but it is it's it's just simply safer. With grippers on both feet you can have more downward pressure and there's that downward pressure thing again. And in a recreational environment you may play with uh two or three or four different teams whether it's in league play or going to bond spills and with some team or teams it's better if you brush from the right side of the rock but for another team it's better on the left side. Well if you're used to brushing with grippers on both feet going from side to side is very easy. There's nothing more awkward than to see someone try to brush with his or her back foot being the slider foot and it should be providing most of the forward momentum. And then something to think about not so much when you're younger but when you're my age if you push glide around a sheet of curling ice for two hours for an 8N game or two and a half hours for a 10 end game you're putting a tremendous amount of pressure on one knee constantly whether you're brushing or just moving around on the ice whereas if you have grippers on both feet you take the pressure off that knee. And then again it's it's about recovery. So if you are brushing a rock from coast to coast so to speak and you are looking for the the nearest medication than if you push glide back into position. Besides the email from me to Glenn about the bunny hop I also wanted to get his views on what he referred to as planking and and I use the old older fashion term snow plowing where for a good portion of the early part of a stone's movement down the ice one brusher will just simply you know press down on the brush head not moving it and and planking until he or she and and their partner get to the point where they can both start brushing and as Glenn said that's very effective and the you know just simply putting pressure down on the brush head in front of the rock makes a difference but you miss the overlapping that that actually brushing does so there's the trade-off there we mentioned how important it is to visually record brushing and as we said in the podcast it's commonplace to use a device a smartphone a uh a tablet to recording deliveries but you should also be recording your brushing make sure that what you think you're doing you are actually doing and then of course number of rotations there is another there is an episode earlier on in the in my podcast called team technical checkup where I mentioned how important it is for the counting of rotations and talked about how important that can be to how stone makes its way into the ice and then lastly and this could have been the very first thing that resonates with me if you are using the complaint material the yellow stuff it polishes the ice it does not scratch the ice it does not lay tracks you are polishing the ice and conspicuous by its absence anywhere in this episode was the D word directional brushing you can influence the curl either positively or negatively you can but not by directional brushing brush half of the path of the product so back win on behalf of all people who are listening to listening to you so thank you very much for your expertise and again I would refer you to the transcript so back to the show notes and click on transcript you will see the text well let's not forget that great very always remind says don't focus too much on the things that can make you start because there are so many things that can make you happy most days day for everyone and until next time