A player’s defensive ability can be measured using blocks and steals.
Block percentage is the percentage of opponents’ 2-point shots that are blocked by an individual player while he’s on the floor.
%Blocks = Total Player's Blocks / (%Min * Opponents' 2-point attempts)
For example, Jeff Otchere of Stony Brook posted a 16.25 block percentage in the 2018-2019 season. A block percentage of 16.25 percent was good for 1st in the country.
Otchere had 78 blocks playing in 44.7% of Stony Brook’s minutes. Stony Brook’s opponents attempted 1889 2-point field goals.
Anything over 8 percent is above average according to KenPom.
Steal percentage is the percentage of possessions that a player registers a steal while he’s on the court.
%Stls = 100 * Steals / (%Min * Team Possessions)
For example, Washington’s Matisse Thybulle recorded a 6.70 steal percentage. This was 1st amongst all players in the 2018-2019 season.
Thybulle posted 126 steals playing in 77.4 percent of his team’s minutes. Washington had about 2437 team defensive possessions.