But in high-pressure situations, like PK shootouts in high-profile tournaments (like the World Cup, Euros, Copa America, Champions League, etc), the conversion rate drops, for 2 reasons:

1. The pressure gets to the kickers, similar to free throws at the end of a tight basketball game

2. In penalty shootouts, at least 5 guys have to take penalties, and sometimes more, so you often get players who don’t have much experience taking them. On most clubs, only 1 or 2 guys kick most penalties. Most other players rarely do. I’ve seen situations where all 11 players have to kick in a PK shootout, including the goalkeepers.