Curling Force Efficiency
It is essential to force your opponent to one point when they have the hammer. Therefore, if your team is able to do this, your team is "force efficient".
The force efficiency statistic reveals the frequency that your team forces your opponent to score one point when they have the hammer. This statistic is calculated by counting all of the times your opponent scored one point with the hammer, and dividing it by the amount of times your opponent scored with the hammer. This statistic excludes all the ends that were blanked during the game.
Over the course of a season, you want your team to be "force efficient". It is best if your team keeps this statistic as high as possible throughout the season. The higher your team's force efficiency, the better.
Let's think about this idea for a moment. For every time your team is not "force efficient", your team is allowing your opponent to score more than one point with the hammer. Therefore, your team is wasting opportunities to force your opponent to score one point with the hammer. (This is assuming that your opponent never steals an end.)
Just like hammer efficiency, a team's force efficiency is also a percentage.
Understanding Force Efficiency
As curling becomes more competitive, the chances that teams steal ends from each other becomes significantly less. Thus, every time your team does not force your opponent to score one point with the hammer, you are allowing your opponent to have a chance of defeating you.
If we assume an ideal curling situation in which teams constantly score with the hammer, thus alternating which team has the hammer each end, your team will only have four opportunities to score with the hammer. Therefore, if you are unable to be force efficient in one of those four ends, you may lose the game. Alternatively, both teams may be highly force efficient, but one team may score more than 2 points with the hammer in 1 of the 8 ends of the game. Therefore, your team must be force efficient, and force your opponent to score one point each time they have the hammer in order to defeat your opponent.