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The 2014 Advanced College Football Stats Glossary

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Here is a glossary for the terms used in the 2014 college football season previews at SB Nation. It is an updated version of this post from 2013.

Kirby Lee-USA TODAY Sports

Adj. Line Yards: An opponent-adjusted version of the line measure derived from the formula found here. The idea is to divvy credit for a given rush between both the runner and the blockers.

Adj. Pace: Part of the offensive footprint, this takes into account both the number of plays a team attempts and the type of play. Since passes, on average, take up less time (thanks to the fact that 30-50 percent of them are incomplete and stop the clock), pass-heavy offenses are prone to run more plays, therefore limiting the effectiveness of a general plays-per-game measure. Adj. Pace takes a team's run-pass ratio into account.

Adj. POE: An opponent-adjusted "Points Over Expected" measure for running backs that looks both at what a runner gained and what would have been expected given the opponents involved. For more information, start here. (NOT IN USE IN 2014.)

Adj. Points: A look at how a team would have performed in a given week if playing a perfectly average team, with a somewhat average number of breaks and turnovers. The idea for the measure is simple: what if everybody in the country played exactly the same opponent every single week? Who would have done the best? It is an attempt to look at offensive and defensive consistency without getting sidetracked by easy or difficult schedules. And yes, with adjusted score you can allow a negative number of points. For more, start here.

Adj. Record: A derivation of Adj. Points, Adj. Record is based on single-game S&P+ performances. This is the record a team would have had playing a perfectly average team, with a perfectly average number of breaks, in each week of the season. Adj. Record gives you a different way to visualize the impact of both team consistency and schedule strength. Since both teams in a given game are being compared to a baseline average (instead of each other), it is conceivable that both teams could end up with an adjusted win or loss.

Adj. Sack Rate: An opponent-adjusted measure of sack rates.

Adj. Score: See Adj. Points.

Adj. TO Margin: What a team's turnover margin would have been if they had recovered exactly 50 percent of all the fumbles that occurred in their games, and if the INTs-to-PDs for both teams was 21 percent (the national average). If there is a huge difference between TO Margin and Adj. TO Margin (in other words, if fumbles, dropped interceptions, or other unlucky bounces were the main source of a good/bad TO margin), that suggests that a team's luck was particularly good or bad and might even out the next season.

Avg. FP. See the Five Factors section at the bottom of this post.

Bend-Don't-Break: Part of the defensive footprint, this is a comparison of a team's Def. Success Rate (efficiency) to its Def. PPP (explosiveness). The higher the number, the higher percentage of a team's overall S&P was made up by success rate, i.e. the more willing a team was to sacrifice efficiency to prevent big plays. (The lower the number, the more likely a team was to take aggressive risks.)

Covariance: Covariance is a statistical tool that provides a measure of the strength of the correlation between two or more sets of random variates. For these purposes, it is used to compare a team's performance (using opponent-adjusted Adj. Score) to the quality of the opponent at hand. Some teams play their best games against their worst opponents, and some teams do the opposite. For more, go here.

Diff. Net Points: A raw average of the points an offense scores on a given drive compared to the points it would be expected to score based on starting field position.

F/+. The official college football ratings of record at Football Outsiders. F/+ is a combination of the Brian Fremeau's Fremeau Efficiency Index (FEI) and my S&P+.

FIVE FACTORS. See the Five Factors section at the bottom of this post.

FP+. See the Five Factors section at the bottom of this post.

Fremeau Efficiency Index (FEI): FEI considers each of the nearly 20,000 possessions every season in major college football. All drives are filtered to eliminate first-half clock-kills and end-of-game garbage drives and scores. A scoring rate analysis of the remaining possessions then determines the baseline possession efficiency expectations against which each team is measured. A team is rewarded for playing well against good teams, win or lose, and is punished more severely for playing poorly against bad teams than it is rewarded for playing well against bad teams. For more, go here.

Garbage Time %Run. An addition for 2014, this looks at how an offense operated when a game was out of reach -- i.e. not within 28 points in the first quarter, 24 in the second, 21 in the third, or 16 in the fourth -- either when a team was winning or losing.

Havoc: The percentage of plays in which a defense either recorded a tackle for loss, forced a fumble, or defensed a pass (intercepted or broken up). If QB hurries were a reliable stat (at the college level, there is far too much inconsistency in how they are recorded), they would be included here, too.

Highlight Yards: The portion of a given run that is credit only to the running back; after a certain number of yards, the line has done its job, and most of the rest of the run will be determined by the running back himself. For more information, start here. An important note, however: a player's per-carry highlight yardage is now calculated as follows: Highlight Yards divided by Opportunities. In this case, Opportunities mean only the carries in which the offensive line "did its job," i.e. carries that went at least five yards. With a different denominator, then, it is possible for a player's Highlight Yards per carry to be much higher than his overall yards per carry.

IsoPPP. See the Five Factors section at the bottom of this post.

Need for Blitzes: Part of the defensive footprint, this compares a team's standard downs sack rate to its passing downs sack rate. The lower the number, the more they were able to generate pressure on standard downs, and the less need for blitzes.

Opportunity Rate: This is the percentage of carries in which the offensive line "does its job" and produces at least five yards of rushing for the runner. (Generally speaking, the first five yards are considered the line's responsibility, the next five are split evenly between the runner and the line, and anything over 10 yards is all on the runner.) See Highlight Yards and Adj. Line Yards for more information.

Passing Downs: Second-and-7 or more, third-and-5 or more, or fourth-and-5 or more. These are downs in which passing is easily the most likely option for gaining the necessary yardage, and defenses hold the upper hand. Offenses typically throw about 67 percent of the time on passing downs.

PD-to-INC. A defensive personality stat, this looks at the percentage of an opponent's incomplete passes that you either intercepted or broke up. This isn't necessarily a quality stat, just a look at general aggressiveness levels.

Points Per Trip inside the 40. See the Five Factors section at the bottom of this post.

Power Success Rate: As used in Football Outsiders' pro line stats, this is the percentage of runs on third or fourth down, two yards or less to go, that achieved a first down or touchdown. Also includes runs on first-and-goal or second-and-goal from the two-yard line or closer.

PPP: Points per play is an explosiveness measure derived from determining the point value of every yard line (based on the expected number of points an offense could expect to score from that yard line) and, therefore, every play of a given game.

PPP+: An opponent-adjusted version of PPP. As with most other "+" measures, it is built around a baseline of 100.0. Anything over 100.0 is better than average, anything below 100.0 is worse than average.

Redzone S&P+. See the Five Factors section at the bottom of this post.

S&P+. A college football ratings system designed by me and derived from the play-by-play and drive data of all 800+ of a season's FBS college football games (and 140,000+ plays). For more, go here.

Standard Downs: First downs, second-and-7 or fewer, third-and-4 or fewer, and fourth-and-4 or fewer. These are the downs in which the offense could conceivably either run or pass and therefore has an overall advantage over the defense. Offenses typically run about 60 percent of the time on standard downs.

Stuff Rate: This is the percentage of runs where the runner is tackled at or behind the line of scrimmage. Since being stuffed is bad, offenses are ranked from stuffed least often (No. 1) to most often (No. 125); for defenses, the opposite is true.

Success Rate: A common Football Outsiders tool used to measure efficiency by determining whether every play of a given game was successful or not. The terms of success in college football: 50 percent of necessary yardage on first down, 70 percent on second down, and 100 percent on third and fourth down.

Success Rate+: An opponent-adjusted version of Success Rate. As with most other "+" measures, it is built around a baseline of 100.0. Anything over 100.0 is better than average, anything below 100.0 is worse than average.

Turnovers Luck: Presented in Points Per Game fashion, Turnovers Luck looks at the difference between a team's Turnover and Adj. TO Margins and, using the average point value of a turnover (~5.0 points), projects how many points a team gained or lost per game last season.

Yards Per Point: A measure long tracked by Phil Steele as a means of looking at teams that were a little too efficient or inefficient the previous season. A positive YPP Margin means a team's offense was less efficient than opponents' offenses, and to the extent that luck was involved, their luck might even out the next year. (NOT IN USE IN 2014 -- OTHER MEASURES ENCAPSULATE WHAT IS COMMUNICATED HERE.)


This is an idea still under development as the 2014 offseason preview series begins. It stems from the work done in this post.

But over time, I've come to realize that the sport comes down to five basic things, four of which you can mostly control. You make more big plays than your opponent, you stay on schedule, you tilt the field, you finish drives, and you fall on the ball. Explosiveness, efficiency, field position, finishing drives, and turnovers are the five factors to winning football games.

  • If you win the explosiveness battle (using PPP), you win 86 percent of the time.
  • If you win the efficency battle (using Success Rate), you win 83 percent of the time.
  • If you win the drive-finishing battle (using points per trip inside the 40), you win 75 percent of the time.
  • If you win the field position battle (using average starting field position), you win 72 percent of the time.
  • If you win the turnover battle (using turnover margin), you win 73 percent of the time.

This is from 2013 college football game data. It's very, very similar from year to year.

These are good odds. And they speak to the fundamentals of football itself. You want to be efficient when you've got the ball, because if you fall behind schedule and into passing downs, you're far less likely to make a good play. You want to eat up chunks of yardage with big plays, because big plays mean both points and fewer opportunities to make mistakes. When you get the opportunity to score, you want to score. And when you give the ball back to your opponent, you want to give them to have to go as far as possible.

There is still work to be done to derive truly isolated, interesting stats from this, but for the time being, the Five Factors will be accounted for in the 2014 season previews in 10 ways -- five adjusted for opponent, five not, and all interrelated:

  1. Efficiency. Success Rate (unadjusted) and Success Rate+ (adjusted). As defined above, success rates examine your efficiency and consistency in staying on schedule and putting yourself in position to move the chains.

  2. Explosiveness. IsoPPP (unadjusted) and IsoPPP+ (adjusted). IsoPPP is the Equivalent Points Per Play (PPP) average on only successful plays. This allows us to look at offense in two steps: How consistently successful were you, and when you were successful, how potent were you?

  3. Field Position. Average Starting Field Position (unadjusted) and FP+ (adjusted). This is mostly self-explanatory, with one important note: An offense is measured by its defense's starting field position, and vice versa. Special teams obviously play a large role in field position, but so do the effectiveness of your offense and defense. So in the team profiles, you'll find Defensive Starting FP in the offensive section and Offensive Starting FP in the defensive section.

  4. Finishing Drives. Points Per Trip Inside the 40 (unadjusted) and Redzone S&P+ (adjusted). Also mostly self-explanatory. These measures look not at how frequently you create scoring opportunities, but how you finish the ones you create.

  5. Turnovers. Using both Turnover Margin and Adjusted Turnover Margin (as defined above), we can take a look at both how many turnovers you should have committed (on offense) or forced (on defense) and how many you actually did. This tells us a little bit about quality and a lot about the Turnovers Luck idea defined above.