The researchers used a small, adjustable replica of a goal post to test players’ perception before and after attempting 10 kicks. While standing in front of the real-life goal, participants were asked to adjust the width and height of the model to scale.
The players’ pre-performance estimations didn’t correlate at all with their subsequent success rate. But after 10 field goal attempts, their perceived goal size was highly correlated with peformance.
Interestingly, the change in players’ perception didn’t just depend on how many goals they missed — it also mattered how they missed their goals. Folks who failed because they didn’t kick high enough perceived the crossbar to be taller, while those who kicked to the side viewed it as more narrow.