Below you’ll find a list of key terms and statistics that will be part of the language of this site. If you are familiar with the world of tempo-free stats, you will have heard of many of them before. We try to give context and a more full explanation of old terms and add some new ones in our pursuit of understanding college basketball as best as we can. If there are other terms that appear on this site or elsewhere that you would like us to define (even if it’s a non-stats related basketball term), please contact us, and we will get back to you and add it to this list if we think it’s suitable. Thanks!
Baseline Tournament Index (BTI): This is the ranking of teams based on our models to project the NCAA Tournament field and its seeding. Our models for at-large selection and seeding helped us to have the third most accurate projection in 2009. The BTI is a ranking system that combines elements of the NCAA’s Nitty Gritty data to sort through the muck of a team’s resume. In general, when an article cites BTI, it is referring to a team’s ranking based on the at-large model. Teams with BTIs in the 40-55 range are on the bubble.
block rate: For teams, this is the percentage of defensive possessions that ends in blocks. For players, this is the number of blocked shots a player records in proportion to the number of defensive possessions he plays. An average team has a block rate of about nine percent. A very good shot-blocking team will have a block rate of about 11 percent. A very good individual block rate is six percent.
defensive rebounding percentage: For a team, this is the percentage of its opponent’s missed shots that it rebounds. For a player, this is the percentage of his opponent’s missed shots that a player rebounds in proportion to his time on the floor. An average team defensive rebounding rate is 67 percent. A very good team defensive rebounding rate is 70 percent. A very good individual defensive rebounding rate is 20 percent or better.
defensive efficiency: The number of points a team allows per possession. Anything less than one point per possession is considered good.
effective field-goal percentage (eFG): This stat attempts to give appropriate credit for the value of a 3-pointer by weighting it 50 percent more than 2-pointers. An average team has an eFG of about 50 percent, and a very good team is around 53 percent. A very good individual eFG is about 58 percent or better.
foul rate: This is the number of fouls a player would be expected to commit if given a certain number of minutes. We’ll calculate it for 30 minutes (a typical workload for a starter) and 40 minutes.
four factors: These are the four primary elements that determine a team’s offensive and defensive success. The factors are effective field-goal percentage/effective field-goal percentage defense, turnover/turnovers forced rate, offensive/defensive rebounding percentage and offensive/defensive free-throw rate.
free-throw rate: This can be calculated in terms of both free throws made and free throws attempted. It’s a rate based on field-goals attempted. Offensive rates are usually calculated based on free-throws made and defensive rates based on free-throws attempted, since a defense can’t really control how well an offense shoots free throws. An average team has a free-throw rate of 24 made free throws per 100 field goals. An average team allows a free-throw rate of 36 attempts per 100 field goals. A very good individual free-throw rate is 50 attempts per 100 field-goal attempts.
minutes percentage: This is the percentage of minutes an individual player plays out of all the minutes a team plays.
NCAA Tournament Conference Score: A simple stat that we came up with to determine the quality of a conference’s performance in the NCAA Tournament. It’s basically the total of a conference’s NCAA Tournament bids plus its wins divided by the teams in the conference (all teams, regardless of whether they make the NCAAs). (During the Tournament, we add the number of teams still alive for each conference to the numerator to give a better reflection of how each conference is doing at a given time.)
offensive efficiency: This is the number of points a team scores per possession. Anything greater than one point per possession is considered good.
offensive rebounding percentage: For a team, this is the percentage of its own missed shots that it rebounds. For a player, this is the percentage of his team’s missed shots that a player rebounds in proportion to his time on the floor. An average team offensive rebounding rate is 33 percent. A very good team offensive rebounding rate is 36 percent. A very good individual offensive rebounding percentage rate is 10 percent or better.
Paymon Score: This is a NCAA Bracketology scoring system created by Paymon of PH Sports. The system gives 2 points if a team has exactly the right seed, 1 point if a team is within 1 seed line, and 3 points for each team correctly picked to be in the tournament. The maximum score for the 65 team tournament is 390.
possessions (Poss): See usage.
Poss/100: This refers to the number of possessions a player accounts for out of 100 team possessions played. It’s simply the usage or possessions rate for a player multiplied by his minutes played. This is a way to measure a player’s importance on a team and how significant his contributions would be to replace.
A very important player accounts for at least 20 Poss/100. Key players will be in the 16-20 range. Important members of a rotation but not go-to players will range from 11-15. Less important rotation players will be in the 6-10 range, and players whose minutes and roll are limited will come in at less than 5.
Ratings Percentage Index (RPI): This is a tool used by the NCAA Tournament Committee to determine relative strength of opposition. It used three measures — a team’s winning percentage (25 percent), a team’s opponents’ aggregate winning percentage (50 percent) and a team’s opponents’ opponents’ aggregate winning percentage (25 percent). The ranking is almost solely used to evaluate the relative strength of teams for the NCAA Tournament. It’s best used to evaluate the quality of team’s opposition, since that’s 75 percent of the formula.
The formula was adjusted before the 2004-05 season to include extra credit for neutral-court and road victories in a team’s winning percentage but not in the other two parts of the index. A road win now counts as 1.4 wins, road loss as 0.6 losses; it’s the reverse for home wins and losses — neutral wins and losses both count as 1.0. This change was made to encourage major-conference teams to play more true road games and also to give appropriate credit to smaller schools who are usually forced to play major-conference teams on that team’s home floor. The concept behind the adjustment is sound, but the adjustment is too large — 1.2 and 0.8 would make more sense and still give 50 percent more credit for a road win than a home win rather than the current, absurd 233 percent difference.
shots percentage: This is the percentage of shots an individual player takes — both field-goal attempts and weighted free-throw attempts (47.5 percent of total free-throw attempts) — as a percentage of all shots his team took while he was on the floor. Obviously, 20 percent is average, while anything above 25 percent means that player is heavily involved in his team’s shooting.
steals rate: For teams, this is the percentage of defensive possessions that ends with a steal. For players, this is the percentage of steals in proportion to the percentage of defensive possessions the player is on the floor. An average team steals rate is 10 percent. A good team steals rate is 11 percent. A very good individual steals rate is three percent or better.
tempo-free: This refers to evaluating teams in relation to possessions played rather than minutes played. It’s a response to the misconceptions that often portray fast-paced teams as worse defensively and better offensively than they are, and the reverse for slow-paced teams. Since teams alternate possessions in basketball, it can be looked at along the same lines as baseball with its innings. No one would evaluate a baseball team’s offense or pitching in relation to the length of the game but rather the number of opportunities -– innings, at-bats. The same should be true in basketball, and that’s from where the idea of tempo-free stats has emerged.
true shooting percentage: This is similar to effective field-goal percentage in that it weights 3-pointers made as 50 percent more valuable than 2-pointers made, but it also includes free-throw shooting to give credit to players who get many of their points at the free-throw line. Sixty percent is a good true-shooting percentage.
turnover rate: For a team, this is the percentage of possessions that ends in a turnover. For a player, this is the percentage of possessions he uses (based on usage) that ends in a turnover. An average team and player turns the ball over about 22 percent of the time. A good ball-handling team turns the ball over about 18 percent of the time.
usage: Sometimes called “possessions,” this is similar to shots percentage in that it attempts to determine a player’s involvement in the offense, but it also includes assists and turnovers so as to properly value players who have a large role in an offense without taking many shots. Again, 20 percent is average and anything above 25 percent is considered a large role.
