Several agility tests are commonly used to assess soccer players, but the most widely accepted and researched one is the Illinois Agility Test. This test measures a player's ability to change direction quickly and is considered a good indicator of on-field performance.

The test is performed on a square grid with each side measuring 10 yards, and the player starts at one corner and runs to the opposite corner following the path marked on the grid. There are different variations of the test, but the most common one involves running around cones placed at the corners of the square grid, in a specific order, usually in a "T" shape or an "L" shape.

The test is timed, and the player's time is recorded. It's a good test for measuring the ability of soccer players to change direction and accelerate quickly, which is essential for their position in the field. It is important to note that the test result should be compared to normative data from the same population and the player’s position on the field.

Other common Agility tests used to assess soccer players are the T-test, Pro-agility test, and the Zig-Zag agility test.