The Power Play in Mixed Doubles Curling, Explained

What is a power play in curling?

A power play is an option in mixed doubles curling that shifts the two pre-positioned stones off the centre line and out to one side of the sheet. Each team gets one per game.

Both stones move together. The in-house stone belongs to the team with the last stone of the end, and it sits where the eight-foot and twelve-foot circles meet, back edge on the tee line. The guard goes to the same side, in front of it. The middle of the house is left empty.

That is the whole idea. Clear the centre, and the team throwing last has a straight route to the button.

It exists only in mixed doubles, a format young enough that it only arrived at the Olympics in PyeongChang in 2018. The four-player game has no pre-positioned stones, so there is nothing to shift.

What are the rules?

Four, and most explainers get the first one slightly wrong.

The power play belongs to the team holding the decision on where the pre-positioned stones go. That is usually the team with the hammer, but the two are not identical and the rulebook says the former. Each team may call it once per game. It cannot be used in an extra end. The calling team picks which side of the sheet.

One further rule makes it work. No stone can be removed from play until the fourth thrown stone of an end, stricter than the four-player free-guard zone, so a power play setup survives long enough to build on. World Curling’s own description of the rule covers the placement in full, and if the vocabulary is the sticking point we have every other word a broadcast throws at you defined in one place.

Why does mixed doubles need a power play at all?

Because mixed doubles reversed the blank end rule, and something had to replace what that took away.

A blank end is one where neither team scores. In the four-player game, blanking keeps the hammer with the team that already had it, so if an end is not shaping up you clear the house, score nothing, and take last stone into a better position next time. That is how blanking works as a tactic.

Mixed doubles does the opposite. Blank an end and the hammer passes to your opponent. The waiting option disappears, and blank ends are close to absent from the format as a result.

So the hammer team has no way to bank an advantage and spend it later. The power play is what they got instead: one chance per game to turn a decent position into a big end. Once it is gone, it is gone.

Everything else here follows from that.

What is a power play actually worth?

About 0.29 points of expected score in the end you call it.

That comes from the Wharton Sports Analytics and Business Initiative, in a research note published on 28 January 2026 by Trey Elder, Samen Hossain and Jonathan Pipping, who modelled every start-of-end situation in top-level mixed doubles and compared calling the power play with saving it.

A second source measures it differently. Robyn Ritchie, Alexandre Leblanc and Thomas Loughin published a dataset covering 1,352 power play ends across eleven tournaments from 2016 to 2025, spanning the World Mixed Doubles Championships and two Olympics. It is a preprint and has not been peer reviewed, which is worth saying. In that data, hammer efficiency, meaning the share of ends with the hammer where a team scores two or more, runs at 35.8% in power play ends against 28.2% in regular ends.

Both figures are mixed doubles only. Hammer efficiency runs higher in the four-player game, so a number from a men’s or women’s broadcast does not transfer.

Together they say something less dramatic than the television framing. A power play is worth roughly a third of a point and about seven percentage points of big-end frequency. Useful. Not transformative. Which is the point, because you only get one.

When should a team call it?

Late, and in a close game.

The Wharton model compares the win probability of calling a power play now against saving it, for every score and every end. With the hammer in the eighth, calling it is worth 8 to 10 percentage points when the scores are level, 10 to 11 when a point down, and 4 to 5 when two down. Late ends carry the most leverage and leave an opponent no time to answer.

Early ends invert that. A power play still adds expected points in the second or third, but spending it there tends to reduce win probability, because a point gained that early can be undone over the ends that follow and the option cannot be recovered. The value sits in holding it.

It is worth more still once your opponent has spent theirs. You are then the only team left who can open the sheet.

The rule of thumb that falls out of all this is short. Save it through the first six ends. Use it in the seventh or the eighth.

One caveat, which the authors make themselves. Teams call power plays for reasons the data cannot see, ice conditions and matchups among them, so treat this as a benchmark rather than a law. The tournament data behind it is published openly.

What do the best teams still get wrong?

The middle of the game.

Accuracy is high in the early ends, where teams correctly hold on, and high again in the seventh and eighth, where they correctly spend. The errors cluster in the fifth and sixth. Teams take the bigger end in front of them and give up roughly 2 to 3 percentage points of win probability in the worst cases. Canada’s timing tracks the model most closely, Finland’s strays furthest.

There is a British detail in the same dataset nobody seems to have pulled out. Scotland scored two or more with the hammer in 37.0% of regular ends and 45.1% of their 71 power play ends. The power play does more for Scotland than for the field.

None of this is easy. A team faces one of these decisions a game, eight or nine across a tournament, so there is almost no chance to learn from getting it wrong. How little published work exists on the question is part of the problem.

We work with the Team GB Foundation and with Olympic curlers including Eve Muirhead, and this is the sort of call that looks obvious from the sofa and is not.

Does ice-free curling have a power play?

No, and there is no sense pretending otherwise.

Ice-free curling has no pre-positioned stones and is not the mixed doubles format, so there is nothing to shift and no option to spend. The rule here belongs to the game you watch on television.

What carries over is the part that makes the rule interesting. Ends, the hammer and the decision about your last stone are all there on a synthetic sheet, and they are what make curling worth playing rather than only worth watching.

If you fancy throwing one yourself, here is what a session actually involves.

Frequently asked questions

How does curling work in mixed doubles?

Two players a team, one man and one woman, throwing five stones each per end across eight ends. Two stones are placed before every end begins, one per team, which is what the power play moves. Scoring works as in the four-player game.

Can both teams use a power play in the same game?

Yes. Each team gets one and the two are independent, so a game can contain two power plays, one, or none. Neither can be called in an extra end.

Why do teams not use the power play in the first end?

Because it is worth more later. Calling it early adds points to that end but surrenders the chance to call it in the seventh or eighth, when one end is far more likely to decide the result.