Frequently Asked Questions
Why hockey?
Hockey is a good setting for this project because it is fast, spatial, and often hard to summarize with simple box-score numbers. A team can take many shots without creating many dangerous chances, while another team can take fewer shots but attack from better areas of the ice. This makes hockey shot data useful for visual storytelling because location, distance, and context all matter.
Who is this website for?
This website is written for hockey fans, beginner sports analytics readers, and students interested in data visualization. The goal is to make shot-quality ideas understandable without assuming the reader already knows advanced hockey statistics.
What question is this project trying to answer?
The main question is: what makes a hockey offense dangerous beyond simply taking a lot of shots?
To answer that, we compare shot volume, shot location, expected goals, player roles, and game situation.
What is a shot event?
A shot event is one recorded attempt toward the net. In this project, we include three types of shot events:
- Shot: a shot on goal that was saved or did not become a goal
- Missed shot: a shot attempt that missed the net
- Goal: a shot attempt that went in
Using all three helps us study chance creation, not only scoring.
What is expected goals, or xG?
Expected goals, usually called xG, estimates how likely a shot is to become a goal based on similar historical shots. For example, an xG value of 0.10 means the shot had about a 10% chance of becoming a goal.
xG is useful because two shots can count the same in a box score but have very different levels of danger. A close shot from the slot is usually more dangerous than a long shot from the boards.
What does shot quality mean?
Shot quality refers to how dangerous a shot is. In this project, we mainly use expected goals, shot distance, and rink location to measure shot quality. A higher-quality shot usually comes from closer to the net, closer to the middle of the ice, or in a situation where the attacking team has more space.
Why does shot distance matter?
Shot distance matters because close shots are much more likely to become goals than long shots. A team that gets the puck into central areas near the net is usually creating more dangerous offense than a team taking mostly long-distance shots from the perimeter.
What does it mean to fold shots into one attacking zone?
NHL teams shoot toward different nets depending on the period. To make shot locations easier to compare, we fold all shots into one attacking zone. This means all shots are shown as if they are moving toward the same net. It makes the rink maps easier to read.
What are central shots and perimeter shots?
In this project, central shots are attempts from the middle attacking area near the slot. These are usually more dangerous because they come from better scoring angles and shorter distances.
Perimeter shots are attempts from farther outside or wider areas of the rink. These shots can still become goals, but on average they are less dangerous than central chances.
Why compare the Colorado Avalanche and Vancouver Canucks?
The Colorado Avalanche and Vancouver Canucks give us a focused case study. Instead of only showing league-wide patterns, we use these teams to show how offensive style can be compared at the team and player level. The point is not only which team is better. The point is how each team creates chances.
What is a power play?
A power play happens when one team has more skaters on the ice because the other team has a player in the penalty box. For example, a 5v4 power play means one team has five skaters while the other has four. Power plays often create better chances because the attacking team has more space and passing options.
What does shorthanded mean?
A team is shorthanded when it has fewer skaters because one of its players is serving a penalty. For example, if a team is defending at 4v5, it is shorthanded.
What is even strength?
Even strength usually means both teams have the same number of skaters on the ice. The most common version is 5v5. Since most of a hockey game is played at even strength, it is an important baseline for comparing shot quality.
What is icing?
Icing is a rule violation that happens when a team shoots the puck from behind the center red line across the opponent’s goal line without it being touched. Play usually stops, and the faceoff comes back to the defending team’s zone.
Icing is useful hockey background, but it is not a major part of our analysis because this project focuses on shot events and shot quality.
What does this project not capture?
This project does not capture every detail that affects a scoring chance. Expected goals is helpful, but it does not perfectly measure screens, goalie movement, defensive pressure, passing before the shot, or whether a player had time and space. The project also focuses on one NHL regular season, so the patterns should not be treated as permanent team identities.
How should I read the website?
Start with the homepage to understand the main story. Then use the overview page to understand the dataset and key terms. Finally, use the case study page to see how the same ideas apply to specific teams and players.
Key Hockey Terms
Offensive zone
The offensive zone is the part of the rink where a team is trying to score. In our rink maps, we fold all shots into one attacking zone so every shot is shown as if it is moving toward the same net.
Defensive zone
The defensive zone is the part of the rink where a team is protecting its own net. A team usually wants to move the puck out of this zone and into the offensive zone.
Neutral zone
The neutral zone is the middle section of the rink between the two blue lines. It is usually where teams transition from defense to offense.
Slot
The slot is the central area in front of the net. Shots from the slot are usually more dangerous because they are closer to the goal and have better shooting angles.
Crease
The crease is the marked area directly in front of the goal where the goalie plays. Shots or rebounds near the crease are often very dangerous because they happen close to the net.
Blue line
The blue line separates the neutral zone from the offensive or defensive zone. Shots from near the blue line are usually farther from the net, so they tend to be lower-danger attempts unless they are screened, tipped, or deflected.
Boards
The boards are the walls around the rink. Shots from near the boards usually come from sharper angles and are often less dangerous than shots from the middle of the ice.
Faceoff circle
Faceoff circles are the circular markings on the ice where play can restart after a stoppage. In shot maps, the faceoff circles are useful landmarks for understanding whether shots come from central areas, wide areas, or farther outside.
Point shot
A point shot is a shot taken by a player near the blue line, often by a defenseman. These shots can create rebounds or deflections, but they are usually less dangerous than close-range chances.
Rebound
A rebound happens when the goalie stops a shot but the puck bounces back into play. Rebounds can create dangerous second chances because the goalie and defense may be out of position.
Screen
A screen happens when a player blocks the goalie’s view of the puck. Screens can make long-distance shots more dangerous because the goalie may not see the shot clearly.
Deflection
A deflection happens when a player redirects the puck after a shot or pass. Deflections can be dangerous because they change the puck’s direction close to the net.
One-timer
A one-timer is a shot taken immediately off a pass without stopping the puck first. One-timers can be dangerous because they give the goalie less time to react.
Rush chance
A rush chance happens when a team attacks quickly after moving the puck up the ice. These chances can be dangerous because the defense may not be fully set.
Cycle
The cycle is when a team keeps possession in the offensive zone by passing and moving the puck around the boards or corners. Cycling can help create space and eventually lead to better shot locations.
Skaters
Skaters are the non-goalie players on the ice. A normal even-strength situation is 5v5, meaning each team has five skaters plus a goalie.
Goalie
The goalie is the player who protects the net. Goalie movement, positioning, and whether the goalie can see the puck all affect whether a shot becomes a goal, though these details are not fully captured in our dataset.