If you’re still collecting frequent-flier miles, you may be missing the points.

Travelers continue to be frustrated by the inability to cash in frequent-flier miles for popular flights. Seats are often limited or nonexistent, and airlines more often ask for huge numbers of miles above basic levels to get award tickets.

But an annual study of award availability shows Southwest Airlines and JetBlue Airways , both of which have point-based loyalty programs instead of using miles as currency for award tickets, had ample availability compared with other airlines.

Southwest had seats available on 100% of the survey’s requests, tying it with Air Berlin for best. JetBlue had availability on 87% of the queries.

Southwest and JetBlue price every seat in cash or an equivalent number of points—the higher the cash price, the more points needed to score the seat. That means there are no capacity controls or limits. If you’re just short of the points needed for one flight, you can often find a cheaper one. With mileage-based programs, airlines restrict availability for award seats and offer them only at fixed prices, such as 25,000 miles for a domestic trip.