FIFA Quality Programme for Virtual Offside Lines

Virtual offside lines (VOL) have been used for several years to graphically analyse potential offside situations in football.

Since the introduction of video assistant referees (VARs) into the Laws of the Game in 2018, there has been an increased spotlight on the ability to accurately determine offsides and make confident decisions based upon these lines. Research carried out by FIFA between 2016 and 2019 showed that the most frequent sources of error for such virtual lines are the topography of the field (particularly the field camber), camera-angle distortion, player occlusion and the issue of tracking individual body parts.

As a result, no two broadcast images ever represent the same scenario, which therefore introduces unknown and unsystematic error to the visualisation of the line. In order to counteract these major influencing factors, this test protocol was developed to ensure that any system that obtains certification can cope with the above-mentioned challenges.

The assessment of virtual offside line systems, to be used in conjunction with VARs, shall be conducted with two distinct test blocks aimed at determining the accuracy and the repeatability of each provider. Testing these systems at more than one location ensures that they are able to consistently perform well. More information on the testing protocol can be found here.

Any provider seeking to test and certify their virtual offside line technology to the requirements of the FIFA Quality Programme needs to follow the certain guidelines, which outlines the process to obtain certification for a system that generates virtual offside lines.

Timeline of VOL Research & Development:

Initial Testing

October 2017 Sandhausen, Germany 

The first stages of 2D and 3D assessements. Comparison based on pixels of the drawn line and the ground truth derived from the cones.

Fine-tuning of Test Method

April 2018, Mainz, Germany

Understanding the main challenges: pitch topography, camera positions, player occlusion, body part offside. This was with a view to formulating a test protocol.

First Official Test Day

October 2018, Valencia, Spain

Applying the test protocol developed during the research phase. Assessing the industry of offside line providers and determining the thresholds for FIFA standard. 

VOL Quality Programme Launch

June 2019

The launch of FIFA Quality Programme for Virtual Offside Lines.The first opportunity to receive the FIFA Quality standard for a certified system.