What coaches should look for in slalom video and GPS data review

Slalom is defined by rhythm, timing, and rapid direction changes. Small tactical differences above a gate can carry through an entire combination. Video shows how the athlete moves. GPS athlete data shows how that movement affects time progression through the course.

This article focuses specifically on slalom. For a broader framework on linking video and GPS data across disciplines, see how to analyze alpine ski racing performance with video and GPS data.

Rhythm and timing through combinations

Hairpins, flushes, and delays are where slalom performance often separates.

• Entry timing. Is the athlete entering the combination with depth, or arriving late and chasing the line?
• Transition speed. Does speed remain stable through the stack of gates, or does it drop after the first redirection?
• Exit shape. Is the athlete set up for the next open gate, or forced into a corrective move?

GPS data helps quantify whether rhythm is being maintained. A visible dip in speed or time progression through a flush often signals that pressure was applied too far below the gate.

Depth above the gate

In slalom, skiing with depth above the gate allows pressure to build in the fall-line. Skiers who pinch their line often feel late and must hook the bottom of the turn.

• Video cue. The athlete’s skis are already across the hill before reaching the gate.
• Data cue. Speed builds too late, or acceleration appears only below the gate.
• Outcome. The next transition becomes rushed, affecting the following gate.

When comparing two runs, look for where acceleration begins relative to the gate. Earlier build-up in the fall-line often corresponds to cleaner exits and better continuity.

Managing tight versus open sets

Course setting influences how GPS patterns appear.

• Tight and swingy sets. Expect sharper changes in direction and greater sensitivity to small tactical errors.
• Open sets. Differences may appear more gradually, especially in exit speed between gates.
• Rutty sections. Variability may increase as athletes adapt to grooves or shelves.

Data does not replace interpretation of the set. It supports it. Coaches should always interpret charts within the context of inspection and terrain knowledge.

Acceleration timing in slalom

Slalom is less about top speed and more about how quickly acceleration resumes after each redirection.

• Quick re-acceleration. Strong runs show acceleration beginning early in the fall-line.
• Delayed acceleration. Late pressure results in flatter or declining speed profiles.
• Compounded effect. Small delays repeated over multiple gates produce measurable time loss.

Instead of watching an entire run repeatedly, identify the section where time difference expands, then jump directly to that combination in the video.

For a detailed walkthrough of side-by-side comparison tools, read how to compare ski runs using video and GPS data.

Explaining slalom performance to athletes

Slalom athletes often feel whether a run was aggressive or controlled, but may struggle to identify exactly where rhythm shifted.

• Use the chart first. Identify the section where performance changed.
• Move to video. Show the tactical difference in entry or exit shape.
• Reinforce continuity. Emphasize how one gate affects the next.

When video and GPS athlete data are linked, feedback becomes more precise. Coaches can move from a general comment about being late to a specific example tied to a measurable change in time progression.

You can see how video and data are connected on the Data-linked video analysis capability page, and how this fits into a daily workflow on How Protern Works.