August 27, 2015

A Gold Medal Performance

By Doug
Bruce in Australia was reading some old posts and sent us comments and questions. These along with my comments (in italics) are reprinted with his permission:  

I've been reading a few of your older posts and was wondering if you could do an analysis of Lijia Xu's extraordinary medal race in the last Olympics? One thing that worked for her, that didn't work in the men's race, was the right side on the beats. In one of the aerial shots there are Lasers way in the background. We can assume that these were the men waiting to start their race. It is interesting that the right side did not work for the men.

She ducked the fleet soon after the start and went right. Was this because she was bailing out and struggling to hold her lane? Usually if you are quick, you stick close to the leaders and match them. For a medal race, she was really taking a risk I thought, but was she? I watched the video again and recall reading that her coach had told her to go right. If that was correct, the risk was not following her coach's instructions.

Her downwind penalty. This rule can be very subjective sometimes. What is your take on her penalty? Was she really breaking Rule 42 at the time? Did she change her style after the penalty? She was still fast! I could not see anything bad, but at 19:00 you could see the judge boat closing in. The announcers said that this was the first yellow flag they had seen so the fleet must have been clean. The call was really picky in my opinion. Thankfully, it did not affect the final results.

After her penalty, she makes ground incredibly quickly to regain the lead. How did she do that in such a competitive fleet? She was lighter than the other leaders, but she also seemed to have picked up some pressure by sailing between NED and GBR. Some call this the 'venturi effect.'

At 20:11, CHI is in the middle perhaps gaining from the 'venturi effect?'
She wanted to go around the right gate but did not have the inside, so she luffed hard and bore away to gain the lead and the mark position. That's not quite how I saw it. She was between NED and GBR about to round the left (or right) gate in second place. At 20:23 GBR tried to cut inside and took CHI's wind, and CHI would have slowed down. So CHI defended by luffing sharply and regained the lead. Great move.

What I find interesting is that the leaders chose the right gate to go left which did not work on the first beat.

When GBR tried to go inside CHI, GBR gave up getting room at the left gate. So why did CHI not simply head for that gate to round and then go right as planned? Luffing two boats, rounding the right gate, and then tacking seemed a lot riskier. And why did GBR give up the left gate?

Would that happen at the front of the fleet in a Masters Worlds? It's very competitive at the front of the fleet. I would not be surprised to see exactly the same moves.

She then gets ballsy and goes right again up the beat. Why didn't she cover? Great question. At 21:27 she tacks away.

Rather than stay with the leaders, CHI does a risky cross to go right on her own.
The factors at that moment:
     ● Cover her competition by continuing left, or
     ● Protect against the boats that were going to the favored right, or
     ● Follow her coach's instructions.

My guess this that she chose the latter, even though it was dangerous because she could easily have fouled NED by tacking. Even on the third beat while in the lead, CHI again chose to go right.

Anything else that for you is significant about her race and what she and her competitors may have been doing differently? Watching the race again, I was impressed by how smooth CHI looked going upwind. The others, especially NED, seemed to be wrestling with their boats.

This was an impressive race because there was a virtual 4-way tie for the gold medal in this medal race. Here's what we can all learn from this gold medal performance:
     ● Have a plan and if you're confident with your speed, stick to it.
     ● Be in shape. CHI did not seem to be breathing at all hard.
     ● Courses now have downwind finishes, so downwind speed rules.

Final comments from Bruce: One thing I had never considered when CHI gained so much so quickly after her penalty was the possibility of the venturi effect. Wow, if that was what it was, it was very powerful. Sure she was the lightweight of the fleet at 60kg but I couldn't imagine her weight making that much of a difference so quickly.

As you say, XU looked so smooth upwind and I also put that down to supreme fitness. She seems quite tallish too, so had great leverage from consistent and seemingly effortless straight leg hiking.

The race was super instructive in so many respects.

6 comments:

  1. Thanks for returning to those Olympic medal races. So many interesting moments to discover and study.
    Moreover, the coverage of both the men's and the women's Laser finals was fantastic.

    Highlights for me:
    The recovery of Xu after the penalty on the downwind leg
    The luff a little later; what a gutsy move!

    Wavedancer


    Wavedancer

    ReplyDelete
    Replies
    1. You are more than welcome.

      Are there other races in particular you'd like to revisit? For example, I really liked the gold medal races of the Star and Finn classes that featured a bunch of really good Laser sailors.

      Delete
  2. Concerning the Rule 42, it seems to me it was for rocking - if you look at her mast going side to side starting at about 18:40, it is noticeably more than the competitors and it seems to be in response to body movements - fairly subtle compared to what most of us would be doing, but I suspect that is it.

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  3. Yes for "Rocking" in Race 11 (medal race) and for "Pumping and Rocking" Race 7:
    http://www.sailing.org/olympics/london2012/results/notices/on_water_jury.php
    She is pretty lucky to have her 2nd Yellow in Medal race otherwise she is well outside the top 3. I understand that given the closeness of results, it was deemed prudent just to split right if the other girls are close and maybe they begin to fight amongst themselves if CHN can just get a few boatlengths ahead. Worth the risk really under the circumstances.

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  4. What strikes me the most is the big difference in down wind technique between Xu and the other girls. Xu's carves are very rhythmic and repetitive. She doesn't seem to be looking for the next wave and then throw in a big pump and carve, she is merely linking almost identical s-curves through out the run. And they are relatively small in comparison to the other's. I guess it's those repetitive style carves which catches the refs attention.

    ReplyDelete
    Replies
    1. Yes, and the judges seemed to be really strict about enforcement. Xu certainly had speed when she needed it.

      We hope that the Rio coverage is as good!

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