Goals Against Average measures the average number of goals the goalkeeper allows for each regulation game. It is adjusted for the minutes the goalkeeper plays.
A lower GAA is a sign of a goalkeeper that allows few goals during a game. A higher GAA is a sign of a goalkeeper that allows too many goals during a game.
Formula – How to calculate GAA
GAA = (Goals Against ÷ Minutes Played) x Minutes in a game of regulation time
As defined by the Lacrosse Statistics guide by US Lacrosse.
- “Goals Against” are the number of goals recorded while the goalkeeper is on the field. Include all goals against during regulation and overtime play. Do not include goals against during a shootout. Rules for what qualifies as a goal can be found in the rules section of World Lacrosse.
- “Minutes Played” are the total number of minutes played by the goalkeeper. Include overtime play. Do not include the time the goalkeeper is playing during a shootout.
- “Game Length” is the regulation game length in the league the goalkeeper is playing. Most lacrosse games are 60 minutes of regulation time.
A goalkeeper is in net for 954 minutes, allows 180 goals in that time, and regulation time for the league is 60 minutes per game:
180 goals against ÷ 954 minutes = 0.188679.
0.188679 times 60 minutes of regulation time = 11.32.
This goalkeeper’s Goals Against Average (GAA) is 11.32
- Wikipedia – Goals Against Average (GAA) and Goalkeeper (Lacrosse) – Wikipedia’s information on GAA and the Goalkeeper position in lacrosse.
- Player statistics from World Lacrosse, National Lacrosse League, and the NCAA Men’s & Women’s leagues.
- Rules of lacrosse from the National Lacrosse League.
- US Lacrosse has a guide for Lacrosse statistics.
- HomeTeam Online has a glossary for Lacrosse terms.