why do they broom in curling

They “broom” (sweep) in curling to control how far the stone travels and how much it curls, not to clean the ice.

Quick Scoop: Why They Broom in Curling

1. The basic idea

When sweepers scrub the ice in front of a moving stone, they slightly warm and smooth the pebbled surface. This thin, briefly melted layer of ice reduces friction so the stone:

• Travels farther down the sheet.
• Runs a bit straighter (curls less) than it otherwise would.

That’s why you often see frantic sweeping when a shot looks too short or like it might over‑curl.

2. What sweeping actually does to the ice

Curling ice isn’t flat and glassy; it’s “pebbled,” with thousands of tiny bumps sprayed on with water. As the broom passes quickly over this surface:

• The friction from the broom head warms the top of those bumps.
• A micro‑film of water forms for a moment.
• The stone rides more easily over that thin film, slowing down less.

No sweeping = more friction, more curl, and the stone stops sooner. Hard sweeping = less friction, less curl, and extra distance.

3. How it changes the stone’s path

Sweepers use this effect in real time to “steer” the stone:

• If they sweep more on one side of the running path, they can slightly influence how much the stone curls.
• Continuous, hard sweeping keeps the rock straighter and lets it travel further toward the skip’s broom (the target).
• Stopping the sweep lets the stone grab the ice and curl more into position.

The changes are subtle, but in curling, a few centimeters can decide the end.

4. Other reasons they have brooms

Besides sweeping, the broom has two other big jobs:

• Balance tool : The player delivering the stone uses the broom like a third leg to stay steady during the slide out of the hack.
• Target marker : The skip holds the broom out in front of the house to show exactly where they want the shooter to aim.

So the broom is a targeting device, a balance aid, and an on‑the‑fly physics tool all in one.

5. Why it’s such a big deal at the Olympics

At modern elite levels (like the Winter Olympics), sweeping is almost an art form:

• Teams train to sweep with consistent pressure and speed.
• They communicate constantly (“light!”, “heavy!”, “curling!”) so sweepers know whether to drag the rock farther or let it curl.
• Equipment rules even get debated, because broom fabrics and heads that are too effective could give an unfair advantage.

That’s why you’ll see so much intense sweeping and yelling during big games: they’re squeezing every last bit of control out of the ice and stone. TL;DR: They broom in curling to warm and smooth the pebbled ice just ahead of the stone so it goes farther and straighter, while also using the broom for balance and as a visual target for aiming.