Goals Against Average (GAA) is a stat used to indicate a team’s capacity to fight for or against the puck when compared to their opposing team. It is usually calculated by taking the total amount of goals scored by an opponent (goals) and dividing it by the number of goals scored by a team (points). For example, if a team scores 10 goals and the opposing team scores 5, the GAA for that game would be (10-5)/2 = 4. The GAA for this game would be equal to the number of goals scored by the home team (10) minus the number of goals scored by the visiting team (5).
In short, it is the amount of goals scored per 100 possessions (e.g. 10 goals in 100 minutes of play). A high GAA indicates a team’s ability to defend their goal, while a low GAA indicates a team’s inability to do so. For example, if a team’s GAA is 3.0 or higher, then that team is considered to be a strong defensemen. Conversely, if a team’s GAA is 2.0 or lower, then they are considered to be a weak defensemen. (Hockey statistic guru Jeff Sagarin created the GAA formula).
Like many other sports, hockey players also track their performance using stats. One of the most fundamental stats used is goals scored. Generally, the more goals a player scores, the more valuable he is to his team. For example, a center who can put the puck in the net more frequently than not is an invaluable asset to any team.
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How Do I Calculate Goals Against Average In Hockey?
If you are interested in calculating the GAA for a hockey game, it’s pretty straight forward. All you need is the box score and some pen and paper. Here’s what you do:
For each team, find the amount of goals they scored and the amount of goals their opponents scored. For example, Calgary Flames scored 7 goals and their opponents NY Islanders scored 5 goals. The total number of goals for that game is 12, so 7+5=12. The NY Islanders are the home team, so their GAA is (12-5)/2=4. The Calgary Flames’ GAA is equal to (7-5)/2=2.
For each game, take the total amount of goals scored by the home team and divide it by the total amount of goals scored by the visitor team. In the previous example, the NY Islanders scored 5 goals and the Calgary 7 goals, so the home team’s GAA is 5/7=0.71 or 71% and the visiting team’s GAA is 7/12=0.58 or 58%. The second part is very simple: take the total amount of goals the home team scored and divide it by the total amount of goals their opponents scored. In the previous example, the NY Islanders scored 5 goals and the Calgary 7 goals, so the home team’s GAA is 0.71 and the opposing team’s GAA is 0.58.
Once you have all the GAs for the home and away team, you can simply add them up to get a final GAA. In the case of the Montreal Canadiens vs. Tampa Bay Lightning game, shown below, the Habs won 4-3, so their GAA is (4+3)/2=2.5.
If you’re looking for a more precise way to calculate GAA, then you can use this formula:
GAA (Goals Against Average) = ( (Home Goals) – (Away Goals) ) / ( (Home Goals) + (Away Goals) ) * 100
The above formula, when applied to our previous example, gives us the following:
GAA = (((7-5)/2) + (5-7)/2) * 100 = 25 * 100=2.5
Therefore, in our example, the Montreal Canadiens’ GAA is equal to (4-3)/2=1.25 or 25% higher than the Tampa Bay Lightning’s GAA of 2.50. In other words, the Habs were able to score more effectively than the Lightning in this one particular game. This is because the Habs had more shots (20 to 12) and the Lightning had fewer blocks (9 to 17) in comparison to the Habs. However, when looking at the Montreal Canadiens’ GAA vs. the season average, we see that they are slightly below average (2.51), while the Tampa Bay Lightning’s GAA is above average (2.56).
Sometimes, when determining a player’s value, you need to look at more than just their stats. For instance, does the player provide leadership? Does he have the ability to play in multiple positions? Is he a top-notch skater? All of these questions must be answered in order to determine a player’s worth. In the case of the Montreal Canadiens vs. the Tampa Bay Lightning game, the Habs had a +1 goal differential (5-4) due to the fact that they scored more goals than the Lightning. Moreover, in the four games prior to this one, the Habs had a +3 goal differential (13-10), which they got by outscoring the competition by a 49-30 margin. In other words, in the four games leading up to the start of the contest, the Habs outscored their opponents by a 55-26 margin. This would indicate that their offensive firepower was on a level higher than Tampa Bay’s.
A final note about goals against average. Just because a team has a high GAA, this does not necessarily mean that they are a good defensive team. For example, the Anaheim Ducks have a high GAA (2.76) but their defense rank 24th out of 30 NHL teams. Just because the Habs had a high GAA in a particular game, it does not mean that they were good on defense. This stat only shows a team’s performance in comparison to their opponents, so to say whether the Habs were good or bad on defense, you would need to look at their performance in comparison to other teams in the league. For example, the Habs defense was only average (4th) in preventing their opponents from scoring in the 2018-19 season, but they were better than the average defense according to Sports Reference. This does not take into consideration that the average team allowed 4.88 goals per game last season, while the Habs allowed 4.19 goals per game – a 15% reduction. This shows that even though their GAA is high, they were a better defense than most teams in the league last season.
Are There Any Popular GAA Stats?
While the previous example was basic, it should have made everything clear as to how to calculate the GAA for a game. However, for the sake of completion, let’s go over some of the more popular stats used in hockey:
1. Win Percentage
This is calculated by taking the total amount of wins (W) and dividing it by the total amount of games played (GP). For example, the Boston Bruins had a winning percentage of.714 in the 2018-19 season — four wins out of seven games played. If you’re looking for a team that is more focused on defense than offense, then the Boston Bruins are a good choice. They allowed the second-fewest goals per game last season (2.68) and had a +12 goal differential (55-43). This shows that their defense was very good and they were able to outscore their opponents by a 14-win margin (49-35).
2. Goals Per Game
Forwards will score goals, so it makes sense that this stat would focus on them. However, to keep things interesting for the readers, let’s take a look at the defensemen who had the highest goals per game (GPG) in the 2018-19 season.
The Boston Bruins’ Zdeno Chara led defensemen in scoring with 23 goals, one clear of teammate Joe Hanks, who had 22 goals. This means that Chara had two goals per game played, while the average defensemen had 0.79 goals per game played. This stat is simply the total amount of goals a player scores, no matter where they come from.