College Football by the Numbers (CFBTN) is the world's most complete repository of interesting college football statistics and statistical analysis. When used properly, it will make readers smarter, more knowleadgeable, more insightful, and, in most cases, better looking. This brief guide explains the basic features and provides links for more detailed explanations. Links followed by (g) point to a glossary entry.

Happy Sailing!




Page Locations:
Quick Links
Main Column
Right Column

Glossary



Quick Links
In the top bar you will find links to key summary statistics, sorted by individual, team, and conference.


1) Individual
A) Stats - Passing, Rushing, and Receiving statistics are listed in sortable columns. In each case, there are two options for setting the number of attempts/receptions necessary for a player to qualify.

i) Passers
a) Passes
b) Yards/Pass
c) Completion Percentage
- Raw: completions per pass attempt
- Opp. Adj.(g): completion% adjusted for the opponent's pass defense rating(g)
- Yards Adj.(g): completion% adjusted for yards per completion
- Adjusted+(g): completion% adjusted for yards/comp. and opp. pass D rating
d) Yards/Catch
e) Opp. Comp% Allowed(g) - Average completion% allowed by opponents, weighted by the number of passes thrown against that opponent.
f) Average Opp. Rating(g) - An individual quarterback's strength of schedule
g) INTs
h) Passes/INT
i) TDs
j) TDs/INT

ii) Runners
a) Carries
b) Yards/Carry
c) Explosive(g) - A runners ability to break a big play
d) Opp. Run D Rating(g) - An individual runner's strength of schedule
e) Adj. Yards/Carry(g) - Yards/Carry adjusted for the strength of schedule
f) Probability of Gaining(g) . . .
- Positive Yards
- 2 Yards
- 10 Yards
g) First Down on Three Carries(g) - Probability that three consecutive carries would result in a first down (ignoring penalties).
h) TDs

iii) Catchers
a) Receptions
b) Rec Yards
c) Yards/Catch
d) Touchdowns
e) % of Team's Receptions
f) % of Team's Receiving Yards
g) Yards/Target
h) TDs/Target
i) Yards/TD

B) Heisman (g) - The Stat-Wise Heisman Rankings rates every offensive player by their statistical performance. Points are awarded for offensive production and contribution to a team's success.

C) Fantasy - Fantasy projections and rankings for the upcoming week.


2) Team
A) Rank- All 120 teams are ranked. All rating and ranking systems except the cRPI are based on iterative fit models. Click "(g)" for more information.
i) BPR (g) - My preferred system for ranking teams
ii) Power (g) - A statistical power rating
iii) Hybrid (g) - This is the rating that best reflects national polls. It is the product of a fancy computer model that accounts for wins and losses, margin of victory, and strength of schedule
iv) SOS-BE (g) - Strength of schedule in terms of becoming bowl eligible
v) SOS-Und (g) - Strength of schedule in terms of going undefeated
vi) Offense/Defense (g) - An Adjusted rating of the scoring offense and defense, adjusted for game tempo.
vii) Run/Pass/Run D/Pass D Eff (g) - Run and pass efficiencies based on yards per play.
viii) cRPI (g) - A more logical (though more technical) variation on the RPI.

A) Rank2 - More team rankings.

B) Summary - Team summary statistics
         i) Season, Season+ - Projected record for regular season games and regular season plus any                 potential conference championship game.
         ii) Win Prob. Div, Conf - Probability that the team will represent the division or conference.
         iii) Bowl Eligible - Probability that the team will be bowl eligible

         iv) Undefeated Reg/Post - Probability that the team will be undefeated at the end of the regular             season or after any potential conference championship game.
         v) Win Probability Distribution - Probability that a team will finish the regular season with that             number of wins

C) Picks - Score predictions for almost all NCAA games in the upcoming week.

D) Pick All - Score predictions for any possible pairing of FBS teams at a neutral site.

E) Champs - Simulation-based probability of winning a national championship. Play - a team's odds of playing in the national championship game. Champs - the odds the team wins the championship game. Opponent - the team's most likely opponent.


3) Conference
A) Rank - see Team:Rank. SOS is the strength of the non-conference schedule
        i) P-Top, -Mid, -Bot - the strength of the top, middle and bottom of the conference, respectively.

B) Standings - Team record in conference and the probability a team will win its division.

C) VS. - Conference records in head-to-head, non-conference matchups.


Main Column
You can find all past blog entries in the middle of the right column in the dropdown menu labeled "More Posts"




Right Column
1) Team Pages - Links to team pages.

2) Past Rankings - Rankings for all teams (with sufficient sample size) since 1900. Teams are ranked by hybrid(g), cRPI(g), performance(g), elo(g), offense and defense(g).

3) Maps: Off, Def (g) - Maps locate teams base on their style of play on offense and defense. Teams with similar styles are close to one another.

4) In-Game Odds (g) - Allows the user to track the the probability that a team will win and cover, and the expected margin of victory (updated line) throughout the course of game.

5)
Links - A list of important external listings.




Glossary
Adj. Yards/Carry - yards per carry is adjusted for the strength of the opponent's run D.
Adjusted+ - A measure of quarterback accuracy. The adjusted+ completion percentage is a quarterback's raw completion percentage adjusted for both the yards per completion - longer passes, ceterus paribus, are more difficult to complete - and the strength of the pass defense the quarterback faced.

BPR - A BCS style ranking system with an important twist. This is my preferred system for ranking teams, but it is not intended to be predictive.

Champs - Essentially, this is the probability that a team will play in/win the national championship. These probabilities are calculated in three steps. First, the current season, up to the bowl games, is simulated thousands of times. Second, team's are ranked by their performance in the season, and the top two are selected to play for the national championship. Finally, the national championship game is simulated. By far the most computationally intensive and error-prone step is in ranking the team's, but champ odds uses a slightly modified variation of the hybrid ranking that is very successful in identifying the top two teams using historical data.

cRPI [*] - The cRPI is a technical variation on the traditional RPI. Like the RPI, the cRPI is a formulaic rating system that considers only wins and losses, not the margin of victory. The cRPI, though, corrects one critical flaw of the RPI. A team's RPI can be hurt after a win, or improved after a loss if the opponent's win percentage is sufficiently low or high, respectively. Instead, the cRPI awards or subtracts points based on the quality of the opponent, so a win against a soft opponent earns a team few points while a win against a tough opponent is worth more points. "cRPI*" = cRPI*100.



Explosive - A measure of a backs explosiveness. A higher value means that a running back is more likely to break a long run. It does not mean that a ball carrier will have a high average yards per carry.

Hybrid - The hybrid is the rating system that best reflects national polls. The Hybrid rating is a compilation of the elo and power ratings, win/loss record, and strength of schedule. I post updated ratings for every FBS team this season and since 1900, and also compute ratings for all NCAA teams in the current season.

In-Game Odds - During a game, the odds that a team will win or lose can rise and fall. With the in-game calculator, you can calculate at any time the odds that a team will win and the expected score differential at the end of the game. Given the pre-game line, you can also calculate the odds that a team will win before the game starts.

Maps - The offense and defense maps are visual representations of the different styles used by college football teams. Comparing teams based on tempo, run to pass ratio, run and pass effectiveness, etc., the maps locate teams so that similar teams are close to one another and dissimilar teams are far apart. The maps are used in team pages to visualize potential matchup issues.
 
Offense/Defense Ratings - these ratings are calculated using an iterative fit model that minimizes the error between predicted points scored based on these ratings and actual points scored. These are then adjusted for the number of possessions in a game. Offense/Defense ratings are a key component of the power ratings, hybrid rankings (as a componenet of the power ratings), and predicted game results.


Opp Adj. - A measure of a quarterback's accuracy. The Opp. Adj. comp% begins with the raw comp% and adjusts it for the quality of the opponent's pass defense. Opponents' pass defenses are rated using an iterative fit model to minimize the error between the expected completion percentage and the real completion percentage.

Opp Run D Rating - The opponent run D rating is the average rating of the defenses a runner faces. This rating is calculating by minimizing the error between the estimated yards per carry (based on the run D rating and the adj yards/carry).

Opp Comp% Allowed - Opponent pass D ratings are measured in two ways. The more simple is the opp. comp% allowed. This is the average completion percentage allowed by a quarterback's opponents, weighted by the number of passes thrown against that opponent. The second method, the average opp pass rating, adjusts the opp. comp% allowed based on the accuracy (Yards Adj.) of the quarterbacks those defenses have faced

Pass/Run/Pass D/Run D Eff - The efficiency ratings measure a team's yards-per-play proficiency. An iterative fit model is used to minimize error between the expected yards per pass/run (calculated by subracting the defense's efficiency from the offense's efficiency) and the actual yards per pass/run. These values are also used to adjust for game specific-matchup issues - a team that depends heavily on the run will perform relatively poorly if they are playing a team that is relatively proficient at stopping the run.

Picks - Every week, CFBTN posts predictions for every NCAA football game. For FBS games, these picks are based on historical patterns, power ratings, performance trends, and matchups based on run and pass efficiencies and ratios. For FCS, division II and division III games are based on performance ratings.


Power - The power ratings ignore wins and losses and focusing on measuring how a team will perform in upcoming games.

Pick All - The same methodology that is used to make picks for real games is applied to any possible FBS matchup.


Probability of Gaining . . . - based on the distribution of yards per run for a back, we can calculate the probability that a back will gain a certain number of yards on a given play. We can also calculate the probability that a back will gain 10 yards on three plays.

SOS-BE - A team's strength of schedule in terms of becoming bowl eligible.


SOS-Und - A team's strength of schedule in terms of going undefeated.

Standings - In addition to posting the standings, CFBTN also posts the probability for each team that it will win outright or share a conference or division title. These probabilities are calculating by simulating every possible outcome and estimating the probability of that outcome.


Stat-Wise Heisman Rankings - Individuals are rated based on the their cumulative statistics (rushing, passing and receiving yards and touchdowns), their performance in big games and losses, and the quality of their team and the opposition faced.


Trend-O-Meter - The Trend-O-Meter tracks a team's performance over the course of a season using non-linear regression techniques.

Yards Adj. - A measure of a quarterback's accuracy as a passer. Yards adj. begins with the raw comp% and adjusts that percentage based on the yards per completion. For example, a quarterback that completes a high percent of short passes will see his completion percentage adjusted downward.