If you look at the numbers, a decently hard shot has the ball travel faster than 20 m/s, so the ball is at the goal line 0.5 seconds after the shot. Now, that m

If you look at the numbers, a decently hard shot has the ball travel faster than 20 m/s, so the ball is at the goal line 0.5 seconds after the shot. Now, that means the goalie has to travel at something like 7 m/s. For comparison, the long jump world record traveled at 10 m/s, but not from a running start. [0] So allowing for reaction time and some delay because the ball need to travel a bit distance before one can see which direction it travels, it is simply not possible to react to a well shot penalty. However, that is numbers for professional sports. In amateur, the ball will be shot at a somewhat lower velocity, and importantly, amateurs are a lot less likely to actually shoot a well placed penalty. So in lower leagues, it is a more reasonable strategy to try to react to the ball. [0] https://www.wired.com/2012/08/long-jump-air-density/ https://www.wired.com/2012/08/long-jump-air-density/