A player's defensive ability can be measured using blocks and steals.
Block Percentage (%Blocks)
Steal Percentage (%Stls)
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, Chinanu Onuaku of Louisville posted a 9.7 block percentage in 2015-2016. A block percentage of 9.7 percent was good for 28th in the country.
Onuaku had 62 blocks playing in 61.5% of Louisville's minutes. Louisville opponent's attempted 1046 2-point field goals.
%Blocks = 100 * 62 / (.615 * 1046) = 9.7
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, Oregon State's Gary Payton II recored a 4.2 steal percentage. This was 12th amongst all players in 2015-2016.
Gary Payton II posted 80 steals playing in 85.9 percent of his team's minutes. Oregon State had about 2191 team possessions.
%Stls = 100 * 80 / (.859 * 2191) = 4.2