There were quotas brought in to limit the number of competitors (particularly from the United States and Canada), which are highly competitive in the two events.
for the 2010 Olympics the quota system limited the competition for men and women's freestyle skiing (moguls, aerials, and ski-cross) to 180 athletes.
With the addition of slopestyle and half-pipe in the Sochi Olympics in 2014 the quotas were increased to 282 total athletes, 26 per country, and 14 per gender.
For example, Canada could have sent 33 participants based on international ranking, however they were limited to 26 quota spots.
For the 2018 Winter Olympics the only country to fill all of its quota spots was the United States.