Taking a penalty puts a vast amount of pressure on both the goalkeeper and the player that takes the penalty. Deciding the direction and the force of the kicked ball depends totally on the shooter. However, it is a bit difficult to predict the outcome.
The goalkeeper has a very small time deciding the corner and making a move there during the penalty kick. After the penalty-taker shoots the ball, the goalkeeper has only half a second to pick which side of the goal to dive to. The average goalie takes approximately 0.6 seconds to get to a specific goal side and a full second to stretch to the goal area's top corner, leaving little time to visualize the ball's flight pattern and direction.
Scientists at the University of Amsterdam have been working on an innovative model that considers both when and where to dive. The limitations that must be fulfilled to effectively save a penalty kick are captured by their affordance-based control model. This takes into account velocity in the lateral direction, and hence the dive’s amplitude and power, as well as scaling goalkeepers' essential actions to their utmost capabilities.
The former study was solely focused on the way goalkeepers chose which goal's side to dive depending on a player's actions during the strike and run-up. Most of this research has been done by looking at how goalkeepers react to video recordings of penalties without diving or jumping. Based on this research, goalkeepers are advised to look for specific visual indicators in a player's kick and run-up.
When we see a series of identical events, we usually make the error of thinking that they are unlikely to happen again in the future. We think that the situation needs to be evened out in some way if we witness the same thing happen a few times and are thus more prone to assume the contradictory outcome. Regardless of what has happened previously, the odds are the same every time a coin is tossed. "Gambler's fallacy" is the notion that a contradictory outcome is because of following a series of identical events. It is a phenomenon that often happens during gambling, especially in casinos with sportsbook products. Goalkeepers are affected by this typical mistake in reasoning, although penalty takers have yet to notice.
During the last 36 years, researchers from University College London reviewed 37 penalty shoot-outs that took place during Uefa European Cup matches and World Cup. They discovered that the activities involved in penalty shoot-outs, such as which side the penalty-taker targets for and which way the goalkeeper decides to jump, can be treated as random events. That is until three successive balls are shot into the same corner of the net. Goalkeepers are prone to the "gambler's fallacy" when this happens.
As we stated the reasons above, it is complicated to predict the penalty direction in most cases. Only the most experienced and (especially) most talented goalkeepers know how to utilize their knowledge to stop the shooter from scoring. Any other way would be less fun for football enthusiasts.