I feel like I've got some really interesting numbers on my last blog, and suggest that visitors give it a look, but I'm pretty stoked about this blog, too. This week I am presenting the Matrix, the culmination of my experiment into college football prediction models (plus whatever refinements I might want to make later).
A quick overview of the matrix. It uses two general ratings--play throughout the season and play weighted by the last games. To find the best ratings, I use an automated trial and error system that runs the teams through the season a few hundred times to find the best fit. I then adjust these two ratings for match ups in the game--offensive and defensive play against the run and pass and home field advantage.
Before we get to this week's picks, I want to quickly review my picks from last week. I finished the day 2-3, but to my credit, Boston College did not deserve to win. Morelli proved me right in Happy Valley, and Sanchez showed that USC's problems go much deeper than the play of the quarterback. I still have a hard time believing the PAC 10 is any good with Arizona State undefeated and Oregon in second (after the beat down they got last year in the Holiday Bowl). If USC is having an off year, the entire PAC 10 drops a few rungs in my opinion.
Now with a few notable picks (in a less exciting week).
Game 1. LSU @ Alabama
The only reason the spread is under 10 is that the game is at Alabama and people are waiting anxiously for Saban to perform some wonder. Keep waiting. I've heard this talk that Nick will bring his A game against his old team - but the coach doesn't play and has players don't have much of an A game. The hard hitting, low scoring game (both teams will complete less than 60% of their passes) will appear closer than it really was.
The Matrix:
LSU by 13 points, 66% of covering a -7.5 point spread
Game 2. Oregon @ Arizona State
It's disappointing to think that the Ducks, after franchise-establishing wins at Michigan and against USC could fall to the Sun Devils and out of national championship contention. It is harder to believe that Arizona State is actually good. I've heard that Oregon has "far and away the best offense in the country." That's a bunch of bologna, but they'll still win this one.
The Matrix:
Oregon by less than a point (51% chance of winning), 31% chance against the 7 point spread
Game 3. Rutgers @ Connecticut
I ragged on Connecticut last week and they proved me wrong. Rutgers' performance, on the other hand, made me look like a prophet. The Matrix favors Rutgers in every statistical category it measures but the score.
The Matrix:
Connecticut by 2.2 (57% chance of winning), toss up against the spread (-2)
Game 4. Wisconsin @ Ohio State
Ohio State will beat up on another very weak Big 10 opponent. The Ohio State University might have a legitimately good team, but the rest of the Big 10 is soft. I understand the South when they moan about a lack of balance in college football - if BC and the OSU play for the national championship at the end of the season, I don't see any good reason to recognize the winner as the best team in the country. In my opinion, if national championship game does not include West Virginia or LSU (both teams that lost only once, on the road, against more talented teams than any that BC and Ohio State play all year), or if it includes any team other than those two, Oregon or Ohio State, I won't bother to watch. But Ohio State, with powerful wins over Akron and Kent State, which is better known for a shooting than football, has played well this season.
The Matrix:
Ohio State by 23 (94% chance of winning), 70% chance against the spread (-15.5)
Game 5. Texas A&M @ Oklahoma
Its a bad week for college football and I could only find 4 games of real importance, so I picked the 5th game as a homer. Stat of the game--the Matrix sees Oklahoma holding the Aggies to 3 yards per carry. I'd like to console myself by saying that A&M was only one stupid call away from beating Oklahoma last year, but the same coach that made that same stupid call (to kick the field goal) made the same stupid call last week against Kansas and seems, in fact, to be perfecting the art of stupid calls.
The Matrix:
Oklahoma by 20 (92% chance of winning), 47% chance against the spread (-21)
The most interesting game this week is Navy at Notre Dame. The Midshipmen haven't pulled out a win in a little less than a half-century (1963, I believe), but this year they get to play the JV. Navy is favored by 3.5, the Matrix gives them less than a point, but my gut tells me it won't be that close. Navy's run attack is good enough to put up points against anyone, and Notre Dame's offense is bad enough to stop themselves on an empty field.
Picks of the week:
I'm not a gambler, and I don't suggest it personally, but I do like outsmarting the folks in Vegas, so I present three games where the Matrix believes they are off the mark.
Illinois is favored by 12 and still the Matrix gives them a 72% chance of covering at Minnesota. Not only do the Gophers have an appallingly bad defense, their offense isn't half as good as the Big 10 likes to believe it is - but they did manage 21 against the might Bison of North Dakota State.
UTEP is favored by 7 at Rice, but they'll win by more than 15, 70% chance of covering. Even Texas, that has struggled against almost everyone this season (including powerhouses like Arkansas State and UCF), blew out Rice.
Iowa State has played tougher in recent weeks against Missouri and, especially, Oklahoma, but they are still one of the worst teams in FBS. Kansas State will cover the 14 point spread and win by 30+, 90% chance against the spread. Need I mention that Iowa State is the only other team against which Texas has looked competent.
Click the image below to see the rest of the picks. Rankings based on the matrix will be released starting next week.
CSV file
Sortable Table
BPR | A system for ranking teams based only one wins and losses and strength of schedule. See BPR for an explanation. |
EPA (Expected Points Added) | Expected points are the points a team can "expect" to score based on the distance to the end zone and down and distance needed for a first down, with an adjustment for the amount of time remaining in some situations. Expected points for every situation is estimated using seven years of historical data. The expected points considers both the average points the offense scores in each scenario and the average number of points the other team scores on their ensuing possession. The Expected Points Added is the change in expected points before and after a play. |
EP3 (Effective Points Per Possession) | Effective Points Per Possession is based on the same logic as the EPA, except it focuses on the expected points added at the beginning and end of an offensive drive. In other words, the EP3 for a single drive is equal to the sum of the expected points added for every offensive play in a drive (EP3 does not include punts and field goal attempts). We can also think of the EP3 as points scored+expected points from a field goal+the value of field position change on the opponent's next possession. |
Adjusted for Competition | We attempt to adjust some statistics to compensate for differences in strength of schedule. While the exact approach varies some from stat to stat the basic concept is the same. We use an algorithm to estimate scores for all teams on both sides of the ball (e.g., offense and defense) that best predict real results. For example, we give every team an offensive and defensive yards per carry score. Subtracting the offensive score from the defensive score for two opposing teams will estimate the yards per carry if the two teams were to play. Generally, the defensive scores average to zero while offensive scores average to the national average, e.g., yards per carry, so we call the offensive score "adjusted for competition" and roughly reflects what the team would do against average competition |
Impact | see Adjusted for Competition. Impact scores are generally used to evaluate defenses. The value roughly reflects how much better or worse a team can expect to do against this opponent than against the average opponent. |
[-] About this table
Includes the
top 180 QBs by total plays
Total <=0 | Percent of plays that are negative or no gain |
Total >=10 | Percent of plays that gain 10 or more yards |
Total >=25 | Percent of plays that gain 25 or more yards |
10 to 0 | Ratio of Total >=10 to Total <=0 |
Includes the
top 240 RBs by total plays
Total <=0 | Percent of plays that are negative or no gain |
Total >=10 | Percent of plays that gain 10 or more yards |
Total >=25 | Percent of plays that gain 25 or more yards |
10 to 0 | Ratio of Total >=10 to Total <=0 |
Includes the
top 300 Receivers by total plays
Total <=0 | Percent of plays that are negative or no gain |
Total >=10 | Percent of plays that gain 10 or more yards |
Total >=25 | Percent of plays that gain 25 or more yards |
10 to 0 | Ratio of Total >=10 to Total <=0 |
Includes
the
top 180 players by pass attempts)
3rdLComp% |
Completion % on 3rd and long (7+
yards) |
SitComp% |
Standardized completion % for
down and distance. Completion % by down and distance are weighted by
the national average of pass plays by down and distance. |
Pass <=0 | Percent of pass plays that are negative or no gain |
Pass >=10 | Percent of pass plays that gain 10 or more yards |
Pass >=25 | Percent of pass plays that gain 25 or more yards |
10 to 0 | Ratio of Pass >=10 to Pass<=0 |
%Sacks |
Ratio of sacks to pass plays |
Bad INTs |
Interceptions on 1st or 2nd down
early before the last minute of the half |
Includes the top 240 players by carries
YPC1stD |
Yards per carry on 1st down |
CPCs |
Conversions (1st down/TD) per
carry in short yardage situations - the team 3 or fewer yards for a 1st
down or touchdown |
%Team Run |
Player's carries as a percent of team's carries |
%Team RunS |
Player's carries as a percent of team's carries in short
yardage situations |
Run <=0 |
Percent of running plays that
are negative or no gain |
Run >=10 |
Percent of running plays that
gain 10 or more yards |
Run >=25 | Percent of running plays that gain 25 or more yards |
10 to 0 | Ratio of Run >=10 to Run <=0 |
Includes the top 300 players by targets
Conv/T 3rd | Conversions per target on 3rd Downs |
Conv/T PZ | Touchdowns per target inside the 10 yardline |
%Team PZ | Percent of team's targets inside the 10 yardline |
Rec <=0 | Percent of targets that go for negative yards or no net gain |
Rec >=10 | Percent of targets that go for 10+ yards |
Rec >=25 | Percent of targets that go for 25+ yards |
10 to 0 | Ratio of Rec>=0 to Rec<=0 |
Includes the top 300 players by targets
xxxx | xxxx |
...
Includes players with a significant number of attempts
NEPA | "Net Expected Points Added": (expected points after play - expected points before play)-(opponent's expected points after play - opponent's expected points before play). Uses the expected points for the current possession and the opponent's next possession based on down, distance and spot |
NEPA/PP | Average NEPA per play |
Max/Min | Single game high and low |
Includes players with a significant number of attempts
NEPA | "Net Expected Points Added": (expected points after play - expected points before play)-(opponent's expected points after play - opponent's expected points before play). Uses the expected points for the current possession and the opponent's next possession based on down, distance and spot |
NEPA/PP | Average NEPA per play |
Max/Min | Single game high and low |
Adjusted | Reports the per game EPA adjusted for the strength of schedule. |
Defensive Possession Stats
Points/Poss | Offensive points per possession |
EP3 | Effective Points per Possession |
EP3+ | Effective Points per Possession impact |
Plays/Poss | Plays per possession |
Yards/Poss | Yards per possession |
Start Spot | Average starting field position |
Time of Poss | Average time of possession (in seconds) |
TD/Poss | Touchdowns per possession |
TO/Poss | Turnovers per possession |
FGA/Poss | Attempted field goals per possession |
%RZ | Red zone trips per possession |
Points/RZ | Average points per red zone trip. Field Goals are included using expected points, not actual points. |
TD/RZ | Touchdowns per red zone trip |
FGA/RZ | Field goal attempt per red zone trip |
Downs/RZ | Turnover on downs per red zone trip |
Defensive Play-by-Play Stats
EPA/Pass | Expected Points Added per pass attempt |
EPA/Rush | Expected Points Added per rush attempt |
EPA/Pass+ | Expected Points Added per pass attempt impact |
EPA/Rush+ | Expected Points Added per rush attempt impact |
Yards/Pass | Yards per pass |
Yards/Rush | Yards per rush |
Yards/Pass+ | Yards per pass impact |
Yards/Rush+ | Yards per rush impact |
Exp/Pass | Explosive plays (25+ yards) per pass |
Exp/Rush | Explosive plays (25+ yards) per rush |
Exp/Pass+ | Explosive plays (25+ yards) per pass impact |
Exp/Rush+ | Explosive plays (25+ yards) per rush impact |
Comp% | Completion percentage |
Comp%+ | Completion percentage impact |
Yards/Comp | Yards per completion |
Sack/Pass | Sacks per pass |
Sack/Pass+ | Sacks per pass impact |
Sack/Pass* | Sacks per pass on passing downs |
INT/Pass | Interceptions per pass |
Neg/Rush | Negative plays (<=0) per rush |
Neg/Run+ | Negative plays (<=0) per rush impact |
Run Short | % Runs in short yardage situations |
Convert% | 3rd/4th down conversions |
Conv%* | 3rd/4th down conversions versus average by distance |
Conv%+ | 3rd/4th down conversions versus average by distance impact |
Offensive Play-by-Play Stats
Plays | Number of offensive plays |
%Pass | Percent pass plays |
EPA/Pass | Expected Points Added per pass attempt |
EPA/Rush | Expected Points Added per rush attempt |
EPA/Pass+ | Expected Points Added per pass attempt adjusted for competition |
EPA/Rush+ | Expected Points Added per rush attempt adjusted for competition |
Yards/Pass | Yards per pass |
Yards/Rush | Yards per rush |
Yards/Pass+ | Yards per pass adjusted for competition |
Yards/Rush+ | Yards per rush adjusted for competition |
Exp Pass | Explosive plays (25+ yards) per pass |
Exp Run | Explosive plays (25+ yards) per rush |
Exp Pass+ | Explosive plays (25+ yards) per pass adjusted for competition |
Exp Run+ | Explosive plays (25+ yards) per rush adjusted for competition |
Comp% | Completion percentage |
Comp%+ | Completion percentage adjusted for competition |
Sack/Pass | Sacks per pass |
Sack/Pass+ | Sacks per pass adjusted for competition |
Sack/Pass* | Sacks per pass on passing downs |
Int/Pass | Interceptions per pass |
Neg/Run | Negative plays (<=0) per rush |
Neg/Run+ | Negative plays (<=0) per rush adjusted for competition |
Run Short | % Runs in short yardage situations |
Convert% | 3rd/4th down conversions |
Conv%* | 3rd/4th down conversions versus average by distance |
Conv%+ | 3rd/4th down conversions versus average by distance adjusted for competition |
Offensive Possession Stats
Points/Poss | Offensive points per possession |
EP3 | Effective Points per Possession |
EP3+ | Effective Points per Possession adjusted for competition |
Plays/Poss | Plays per possession |
Yards/Poss | Yards per possession |
Start Spot | Average starting field position |
Time of Poss | Average time of possession (in seconds) |
TD/Poss | Touchdowns per possession |
TO/Poss | Turnovers per possession |
FGA/Poss | Attempted field goals per possession |
Poss/Game | Possessions per game |
%RZ | Red zone trips per possession |
Points/RZ | Average points per red zone trip. Field Goals are included using expected points, not actual points. |
TD/RZ | Touchdowns per red zone trip |
FGA/RZ | Field goal attempt per red zone trip |
Downs/RZ | Turnover on downs per red zone trip |
PPP | Points per Possession |
aPPP | Points per Possession allowed |
PPE | Points per Exchange (PPP-aPPP) |
EP3+ | Expected Points per Possession |
aEP3+ | Expected Points per Possession allowed |
EP2E+ | Expected Points per Exchange |
EPA/Pass+ | Expected Points Added per Pass |
EPA/Rush+ | Expected Points Added per Rush |
aEPA/Pass+ | Expected Points Allowed per Pass |
aEPA/Rush+ | Expected Points Allowed per Rush |
Exp/Pass | Explosive Plays per Pass |
Exp/Rush | Explosive Plays per Rush |
aExp/Pass | Explosive Plays per Pass allowed |
aExp/Rush | Explosive Plays per Rush allowed |
BPR | A method for ranking conferences based only on their wins and losses and the strength of schedule. See BPR for an explanation. |
Power | A composite measure that is the best predictor of future game outcomes, averaged across all teams in the conference |
P-Top | The power ranking of the top teams in the conference |
P-Mid | The power ranking of the middling teams in the conference |
P-Bot | The power ranking of the worst teams in the conference |
SOS-Und | Strength of Schedule - Undefeated. Focuses on the difficulty of going undefeated, averaged across teams in the conference |
SOS-BE | Strength of Schedule - Bowl Eligible. Focuses on the difficulty of becoming bowl eligible, averaged across teams in the conference |
Hybrid | A composite measure that quantifies human polls, applied to converences |
Player Game Log
Use the yellow, red and green cells to filter values. Yellow cells filter for exact matches, green cells for greater values and red cells for lesser values. By default, the table is filtered to only the top 200 defense-independent performances (oEPA). The table includes the 5,000 most important performances (positive and negative) by EPA.
Use the yellow, red and green cells to filter values. Yellow cells filter for exact matches, green cells for greater values and red cells for lesser values. By default, the table is filtered to only the top 200 defense-independent performances (oEPA). The table includes the 5,000 most important performances (positive and negative) by EPA.
EPA | Expected points added (see glossary) |
oEPA | Defense-independent performance |
Team Game Log
Use the yellow, red and green cells to filter values. Yellow cells filter for exact matches, green cells for greater values and red cells for lesser values.
Use the yellow, red and green cells to filter values. Yellow cells filter for exact matches, green cells for greater values and red cells for lesser values.
EP3 | Effective points per possession (see glossary) |
oEP3 | Defense-independent offensive performance |
dEP3 | Offense-independent defensive performance |
EPA | Expected points added (see glossary) |
oEPA | Defense-independent offensive performance |
dEPA | Offense-independent defensive performance |
EPAp | Expected points added per play |
This comment has been removed by a blog administrator.
ReplyDeleteI discovered a slight glitch in the program and so I've made some slight changes to the numbers.
ReplyDelete