Disclaimer: CurlingZone does not represent or endorse the accuracy or reliability of any Content posted on any Forums area and you acknowledge that any reliance upon such Content shall be at your sole risk. Any Content placed on any Forums area by users and anonymous posters are the views of the user posting the statement, and do not represent the views of CurlingZone or our partners, advertisers or sponsors. By posting anonymously, you are allowing your IP address to be displayed for identification purposes. CurlingZone reserves the right to remove any post at its discretion without warning or explanation.
02-28-20 10:35AM |
|
Tony Hladun
Harvey Hacksmasher
Registered: Feb 2019
Location:
Posts: 35 |
Sweeping Article in Curling News
Excellent article about sweeping by Eugene Hritzuk in the March 2020 issue of The Curling News.
If you can’t read it here’s my summary.
With current legal brooms there is no “scratch sweeping” effect. Instead, it’s the mechanical friction of sweeping that warms the ice and reduces friction.
Both sweepers can sweep across the full face of the rock to increase its travel. The article discusses the pressure of a broom stroke and that has some effect. Read the article for the details.
Sweeping one side of the rock (corner sweeping) does affect curl. There’s a diagram in the article but here’s the summary. Sweeping the slow side (reverse rotation) side of a rock makes it run straighter. Sweeping the fast side (forward rotation) makes it curl. I remember it by a simple mnemonic “Slow straight—Fast curl”.
Unfortunately many sweepers at the pro level don’t do this. The skip/third calls the sweep as I’ve described but the sweeper reaches across the rock and does it wrong. It’s not the side the sweeper is on but it’s where he/she sweeps that determines what happens. I hope that gets fixed.
Report this post to a moderator | IP: Logged
|
|
03-01-20 10:34PM |
|
TBT
Knee-Slider
Registered: Sep 2014
Location:
Posts: 5 |
Very interesting. But as you say, none of the pros seem to agree with Eugene. Makes me wonder why I should accept his findings over theirs. I can't read the article, but I'm always persuadable by sound science.
Report this post to a moderator | IP: Logged
|
|
03-02-20 10:51AM |
|
Tony Hladun
Harvey Hacksmasher
Registered: Feb 2019
Location:
Posts: 35 |
quote: Originally posted by TBT
Very interesting. But as you say, none of the pros seem to agree with Eugene. Makes me wonder why I should accept his findings over theirs. I can't read the article, but I'm always persuadable by sound science.
That's a very good question. For the sake of brevity I omitted how Eugene came to his conclusions. He and the University of Saskatchewan used high resolution cameras to determine there was no scratching. The science looks sound but I agree with you the old beliefs are strong.
Report this post to a moderator | IP: Logged
|
|
03-02-20 01:23PM |
|
windy
Harvey Hacksmasher
Registered: Dec 2003
Location:
Posts: 19 |
You can be pretty certain the elite teams know if their directional sweeping is working. The link below is a reminder of where we were before abrasive fabrics and hair were banned. I think the top teams know it is a combination of scratching and heat (max pressure on the correct side of the rock path).
https://youtu.be/haEuz42YCdM
Report this post to a moderator | IP: Logged
|
|
03-02-20 06:21PM |
|
curlingclips
Super Rockchucker
Registered: Oct 2019
Location:
Posts: 1523 |
I'm a new fan, so I missed out on the whole broomgate era, and had to reconstruct the pieces from old interviews and archival footage.
I thought the biggest problem with broomgate was when the broom was used on a rock that was purposefully overthrown, to make it dive bomb and slow down? And that this was super effective but only for a a few shots, so you had to use it sparingly, so you had to manage your brooms, transferring them from one player to another, etc?
The Koe (CAN) vs Stjerne (DEN) from WMCC2016 shows this ( https://www.youtube.com/watch?v=GD50OHvdyDY ). There's also more discussion from Koe (CAN) vs Shuster (USA) ( https://www.youtube.com/watch?v=EI0zaeZm7AI ).
There's still a lot of footage from that era that I haven't watched, so maybe I'm completely wrong about this.
Report this post to a moderator | IP: Logged
|
|
03-03-20 11:20AM |
|
Tony Hladun
Harvey Hacksmasher
Registered: Feb 2019
Location:
Posts: 35 |
curlingclips & windy, those are excellent examples of a past era. That is not curling today so don't get mixed up. Eugene's work is focused on the brooms that are in use today and how to correctly sweep with them. The effect of current brooms is much less than what you see in your videos but remember that burying a rock or a take-out is often determined by inches.
Report this post to a moderator | IP: Logged
|
|
03-07-20 10:44PM |
|
RockDoc
Swing Artist
Registered: Apr 2005
Location:
Posts: 399 |
The left/right friction asymmetry theory of curl was disproved on physical principles in the 1930s. So the asymmetric effects of corner sweeping are not sufficient to explain or control curl. The Nyberg model does explain directional sweeping, but the conforming fabric is much less effective than that used previously. Uncoated nylon is still harder than ice. Silicone or PVC coated nylon is harder and more durable.
I notice the top Brier teams are still apparently utilizing the Nyberg-guided idea of sweeping at a steep angle to try to establish some control over curl, apparently successfully.
Last edited by RockDoc on 03-07-20 at 10:46PM
Report this post to a moderator | IP: Logged
|
|
03-08-20 07:31AM |
|
dks
Hitting Paint
Registered: Oct 2012
Location:
Posts: 119 |
I think brushing affects the rocks both with the polishing and scratching of the ice surface. If I understand the study discussed, the photos show minimal scratching with competition brush heads. What isn’t known is if this minimal scratching is enough to affect the rock. As stated earlier, 1 mm difference might be all you need to make a shot. What i want to know if having 1 or 2 sweepers to hold line has been studied and proven for effectiveness. If you watch Koe’s last shot to win last year’s Brier both sweepers were brushing to hold the line. However, in most shots they were using one sweeper.
Report this post to a moderator | IP: Logged
|
|
03-08-20 10:48PM |
|
Tony Hladun
Harvey Hacksmasher
Registered: Feb 2019
Location:
Posts: 35 |
Brier final tonight...last rock first end, Martin is called to sweep the rock to curl but instead he reaches over and sweeps the rock to run straight and they miss the take out. Bottcher's team never recovers and they commit several more sweeping errors. Probably cost them the game. Sad.
Look at the side he's sweeping at 0:20 of this video https://www.youtube.com/watch?v=uaTWAcmdITM and remember "slow straight, fast curl".
Last edited by Tony Hladun on 03-09-20 at 10:43AM
Report this post to a moderator | IP: Logged
|
|
03-09-20 09:55PM |
|
biterbar
Drawmaster
Registered: Mar 2009
Location:
Posts: 695 |
They know how to sweep. They are not doing it wrong. Put on a EQ head and try it your self.
These are professionals. To think some keyboard jockey knows more than them is incredibly naive.
__________________
"He has all the virtues I dislike and none of the vices I admire"-Winston Churchill
Report this post to a moderator | IP: Logged
|
|
03-10-20 10:02AM |
|
Tony Hladun
Harvey Hacksmasher
Registered: Feb 2019
Location:
Posts: 35 |
biterbar, quit cursing at me and look at the video. If you want to take on someone your size go after The Curling News that published what I had just summarized. For the record, I do curl and I do sweep like the article says and it makes a difference. Also I have a degree in engineering physics and a masters degree in mechanical engineering so I do understand the science.
Report this post to a moderator | IP: Logged
|
|
03-14-20 06:17PM |
|
biterbar
Drawmaster
Registered: Mar 2009
Location:
Posts: 695 |
quote: Originally posted by Tony Hladun
Eugene Hritzuk pointed out to me that Dunstone were using his techniques and if you watch this video he's right. https://www.youtube.com/watch?v=6CG-PIgxtr4 There's no reaching across the rock to corner sweep the wrong side.
I have never cursed anyone on this site. Got to 39:50 and Dunstones front end used the reach over method to hold the stone. It took me 2 minutes to find it. And Gushue, the three time Brier winner, uses it every shot.
__________________
"He has all the virtues I dislike and none of the vices I admire"-Winston Churchill
Report this post to a moderator | IP: Logged
|
|
03-15-20 10:15AM |
|
Tony Hladun
Harvey Hacksmasher
Registered: Feb 2019
Location:
Posts: 35 |
At 39:50 it's the end of a Gushue rock and Nichols has been corner sweeping it to curl which is what they wanted. The next Dunstone rock is not swept at all because they want it to curl and stop so that's OK as well. So biterbar, what are you looking at?
Report this post to a moderator | IP: Logged
|
|
03-15-20 01:14PM |
|
biterbar
Drawmaster
Registered: Mar 2009
Location:
Posts: 695 |
Ok, go to 37:00. Perfect example as is the sweeping by Gushue on the next shot.
__________________
"He has all the virtues I dislike and none of the vices I admire"-Winston Churchill
Report this post to a moderator | IP: Logged
|
|
|
All times are GMT. The time now is . |
|
|
|
|
|
Forum Rules:
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
|
HTML code is OFF
vB code is ON
Smilies are ON
[IMG] code is ON
|
|
|
|
|
|