Zeus (football computer program)
Encyclopedia
Zeus is a computer program developed by End Game Technologies that models and predicts the outcomes of coaching decisions in American football
games. The program is designed to produce statistical outputs showing the expected odds of winning given choices of potential play calls and roster choices. It is capable of simulating 1,000,000 games in a few seconds, and was developed using extensive research on historical data from National Football League
games. It expresses its output in terms of Game Winning Chance, which is the probability that the specified team will win the current game. It also evaluates its output using a range of possible "worst case" scenarios to determine a Confidence Factor of 1 to 10 for its results.
Zeus is particularly geared toward evaluating situations where a coach has essentially two or three play decisions which the opposing team will recognize. An example would be if a team is on fourth down and short yardage, and needs to decide between trying to get first down, punting
or kicking a field goal
. In such a case, Zeus will output its analysis of the game winning chance if you punt versus if you try a short yardage play or kick the field goal. Another example would be, when your team is preparing to kick off, the chance of winning if you kick off normally versus attempting an onside kick
.
An example of Zeus' output is its analysis of Super Bowl XL
between the Pittsburgh Steelers
and the Seattle Seahawks
. Pittsburgh's play calling in "binary" situations exactly matched Zeus' evaluation of the optimal play choice. By contrast, Seattle's play calls differed in six instances, with a combined game winning probability difference of 8.40%, meaning that Zeus estimates that if Seattle had followed its play calls exactly then Seattle would have had an 8.4% better chance of winning the game.
Using Zeus' estimates of differences between its play calls and actual calls by coaches, the program's developers estimate that NFL teams lose on average roughly one game per season due to improper play choice in the binary situations described above.
One common example of where Zeus' recommendation differs with real life coaches is onside kicks. Coaches tend to avoid onside kicks as being too risky, but Zeus sometimes evaluates that the potential gain of a successful onside kick outweighs the risk of failing to recover the ball. Similarly, it tends to be more aggressive in trying for first down conversions, as the potential gain of a first down can outweigh the benefit of trying a safer play like a field goal. Overly emphasizing risk aversion and choosing the "safer" play is, according to Zeus, a shortcoming in human coaches.
American football
American football is a sport played between two teams of eleven with the objective of scoring points by advancing the ball into the opposing team's end zone. Known in the United States simply as football, it may also be referred to informally as gridiron football. The ball can be advanced by...
games. The program is designed to produce statistical outputs showing the expected odds of winning given choices of potential play calls and roster choices. It is capable of simulating 1,000,000 games in a few seconds, and was developed using extensive research on historical data from National Football League
National Football League
The National Football League is the highest level of professional American football in the United States, and is considered the top professional American football league in the world. It was formed by eleven teams in 1920 as the American Professional Football Association, with the league changing...
games. It expresses its output in terms of Game Winning Chance, which is the probability that the specified team will win the current game. It also evaluates its output using a range of possible "worst case" scenarios to determine a Confidence Factor of 1 to 10 for its results.
Zeus is particularly geared toward evaluating situations where a coach has essentially two or three play decisions which the opposing team will recognize. An example would be if a team is on fourth down and short yardage, and needs to decide between trying to get first down, punting
Punt (football)
In some codes of football, a punt is a play in which a player drops the ball and kicks it before it touches the ground. A punt is in contrast to a drop kick, in which the ball touches the ground before being kicked....
or kicking a field goal
Field goal (football)
A field goal in American football and Canadian football is a goal that may be scored during general play . Field goals may be scored by a placekick or the now practically extinct drop kick.The drop kick fell out of favor in 1934 when the shape of the ball was changed...
. In such a case, Zeus will output its analysis of the game winning chance if you punt versus if you try a short yardage play or kick the field goal. Another example would be, when your team is preparing to kick off, the chance of winning if you kick off normally versus attempting an onside kick
Onside kick
In American and Canadian football, an onside kick is a type of kick used at a kickoff or other free kick, or scrimmage kick or other kick during play, in which the ball is kicked favorably for the kicking team to avoid giving away the ball...
.
An example of Zeus' output is its analysis of Super Bowl XL
Super Bowl XL
Super Bowl XL was an American football game pitting the American Football Conference champion Pittsburgh Steelers against the National Football Conference champion Seattle Seahawks to decide the National Football League champion for the 2005 season...
between the Pittsburgh Steelers
Pittsburgh Steelers
The Pittsburgh Steelers are a professional football team based in Pittsburgh, Pennsylvania. The team currently belongs to the North Division of the American Football Conference in the National Football League . Founded in , the Steelers are the oldest franchise in the AFC...
and the Seattle Seahawks
Seattle Seahawks
The Seattle Seahawks are a professional American football team based in Seattle, Washington. They are currently members of the Western Division of the National Football Conference in the National Football League . The team joined the NFL in 1976 as an expansion team...
. Pittsburgh's play calling in "binary" situations exactly matched Zeus' evaluation of the optimal play choice. By contrast, Seattle's play calls differed in six instances, with a combined game winning probability difference of 8.40%, meaning that Zeus estimates that if Seattle had followed its play calls exactly then Seattle would have had an 8.4% better chance of winning the game.
Using Zeus' estimates of differences between its play calls and actual calls by coaches, the program's developers estimate that NFL teams lose on average roughly one game per season due to improper play choice in the binary situations described above.
One common example of where Zeus' recommendation differs with real life coaches is onside kicks. Coaches tend to avoid onside kicks as being too risky, but Zeus sometimes evaluates that the potential gain of a successful onside kick outweighs the risk of failing to recover the ball. Similarly, it tends to be more aggressive in trying for first down conversions, as the potential gain of a first down can outweigh the benefit of trying a safer play like a field goal. Overly emphasizing risk aversion and choosing the "safer" play is, according to Zeus, a shortcoming in human coaches.