Edge Similarity - the secret sauce of great skiers

By Team Carv

September 23, 2020

6 min read

Have you watched expert skiers flying down the steeps, dancing in the moguls, carving down groomers and getting their hip to the ground? I bet you can’t help but wonder if you’ll ever ski like that, or how on earth they became that good?

Expert skiers didn’t get to this level by just skiing the most difficult run they can find. Instead, they deliberately tune their basic skills on moderate slopes.

In this article, we’ve harnessed the power of Carv’s data to investigate the hallmarks of an expert ski turn. We’ve pulled together data from over 200 Carv skiers on the same run (to keep things fair) to uncover the main difference between the technique of experts and intermediates:

Where: Webster, Deer Valley Resort, USA – a green run (and the most skied single run in our database)
Who:
200 Carv skiers (data anonymised)
What:
1139 laps of the run
When:
2019/2020 season

Webster run in Deer Valley, Utah | © Deer Valley Resort

How did we do it?

We assigned the 200 skiers into 5 ability groups based on their Ski:IQ, so we could look across Carv’s metrics and find the most interesting differences to share.

  1. Early intermediate (Ski:IQ 100-110)
  2. Mid Intermediate (Ski:IQ 110-120)
  3. Intermediate/advanced (Ski:IQ 120-130)
  4. Advanced (Ski:IQ 130-140)
  5. Expert (Ski:IQ 140+)

Let’s jump right in.

Did experts ski with a higher edge angle?

We all want to get our hip down to the ground in an amazing carve. The question is, did the experts skiing Webster in Deer Valley turn with a higher edge angle than intermediates?

Each run on the Webster piste by a Carv skier is represented by a dot in the following plots.

Better skiers achieve higher edge angles

Skiers with a higher Ski:IQ consistently achieved higher edge angles in Webster, Deer Valley

We can clearly see that advanced and expert skiers were able to generate a higher edge angle in their turns. Not exactly a revelatory finding, but this step is an important set up for the next question we asked.

What does an expert skier do differently?

Now we know everyone’s edging ability on each run, we wanted to look at other hallmarks of great skiing. However, many elements of technique change as you create higher edge angles, so we wanted to find out what experts do differently to intermediates in turns of the same edge angle.

The answer?

Expert skiers have near-perfect edge similarity.

Edge similarity measures the similarity in the way each ski is rolled. Are we rolling each ski from edge to edge in perfect unison, or is the outside ski leading the way while the inside ski gets hung up under the body?

We can learn 2 interesting things from our 200 skiers in Deer Valley.

1. Better skiers ski with a higher edge similarity

  • A skier who can roll the skis together has a stronger technique, as this skill is very challenging for intermediates to do with perfection.
  • At the beginner end, skiers need to brace their outer ski into a snowplough, but being able to move with your skis in unison is the result of years of training.
  • Put simply, edge similarity is a hallmark of skiing beautiful turns.

Skiers of a higher ability can generate higher edge similarity

2. At any given edge angle, expert skiers have near perfect edge similarity

  • This shows that great skiers are moving their skis in near-perfect unison at both low and high edge angles.
  • In real life, we usually notice this beautiful skiing from the chairlift and look on with jealousy.

The graph below shows the relationship between the Edge Angle and the Edge Similarity (both scaled to between 0 to 1).

Experts ski with higher edge angles, and higher edge similarity. The dream!

It is almost impossible to fake very high edge similarity, and only our top pros have been able to achieve 95% edge similarity or higher.

How can I see my edge similarity?

The Carv app has many features that allow you to both see and improve your edge angle and similarity.

  1. Analyse your own Edge similarity score for each run.
  2. Use the Edge similarity monitor to hear if your skis are moving in unison - live on every turn.
  3. Develop your edging with the Carving Training and Outside Ski Turns drills.

Let's break down edge similarity a bit...

Much of your turning technique is set up at the start of the turn – the entry phase. To uncover more insights about edge similarity, we looked at how each of our skiers’ feet moved in the initial phase of the turn. We investigated:

  1. The Early Inside Ski Roll Rate
  2. The Early Outside Ski Roll Rate

These describe the rate of change of the ski edges during the initial phase of the turn.

When we dig into the detail, our data is showing one critical difference which holds the clue to great ski technique.

Intermediates struggle to roll the inside ski at the start of the turn.

In other words, they are relying on the outside ski to do the work to start the turn, then the inside ski is left to ‘catch up’.

Watch the changing graphic below to see the difference in roll rate between inside and outside ski for intermediates.

Intermediates roll their skis at different rates (the blue dots are more spread out and lower for the inside ski)

Experts roll their ankles in unison.

Carv’s data show that all else being equal, expert skiers manage their inside ski better at the start of the turn. This is the reason they can create better edge similarity and a big part of why they can ski with more style and control. Their turning platform (their skis) is consistent and able to handle anything the mountain throws at them.

There is very little difference between the rate of rolling of the outside and inside ski in the expert ski runs (the green dots do not move much)

"Expert skiers manage their inside ski better at the start of the turn."

OK, so how can I improve my own skiing?:

Here are two things you can do:

1. Let the inside ski decide how much angle you get during the turn.

  • If you want a higher edge angle, tip your inside ski onto the little toe edge more.
  • Don’t rely on your outside ski carrying your turn. You may need to ski faster and incline more into the turn to allow the inside ski to lead the turn.
  • This exercise does not mean your weight should now be on your inside ski, in fact you’ll find it harder to roll your inside ski if it is. Keep your pressure against the outside ski.

Try the Edge Similarity monitor

2. Use the Edge Similarity monitor and ski a railroad drill. The Edge Similarity monitor is a Carv feature that plays your edge similarity live into your ear.

  • Use this on a green slope and ski railroads – concentrate on moving your ankles and knees together on small turns – barely moving, just creating clean tracks in the snow behind you.
  • Lead with your ankles and notice what you’re doing when you score over 80%, and what you’re doing differently when you score under 80%.
  • Gradually push your turn radius bigger and bigger without sacrificing edge similarity scores.

Now get out there and go from good to great!


Want to improve your skiing?

Written by: Team Carv