Top Twenty (3/9)

Rank	Change	Name	Rating
1	+1	Florida	33.7
2	-1	Indiana	33.6
3	+4	Louisville	33
4	-1	Gonzaga	32.5
5	+5	Duke	32.3
6	-2	Kansas	32.2
7	-1	Michigan	32.1
8	+1	Syracuse	31.7
9	+4	Pittsburgh	31.7
10	-2	Ohio St.	31.6
11	-6	Wisconsin	31.1
12		Michigan St.	31
13	NR	Missouri	30.8
14	NR	Miami (FL)	30.7
15	NR	VCU	30.7
16	-5	Oklahoma St.	30.7
17	NR	Creighton	30.6
18	NR	Arizona	30.5
19	-4	Minnesota	30.5
20	-3	Georgetown	30.4

You'll note the rating scale and other significant changes.  I was getting bored with the old Top Twenty, so I've adjusted the Prediction Machine to use a different rating algorithm, to give a bit of a different look at the teams.

Regardless of the rating algorithm, Florida and Indiana remain the class of the field, although Louisville closes the gap with the new rating.   Louisville has fallen in and out of favor with the pundits, but hasn't had a bad loss since 1/22 against Villanova.  Duke and Pittsburgh are other teams moving up, and the big losers here are Wisconsin (losers of two straight, including Purdue), Oklahoma State (lost to Iowa State), Minnesota (lost to Nebraska!?) and Georgetown (lost to Villanova).  Georgetown's hopes for a #1 seed rest on winning today at Syracuse and then winning the Big East tournament.  The lesson here, if there is one, is don't lose late-season games to weak opponents.

Several surprise teams appear in the bottom of the list, including Missouri, Creighton and Arizona.  Despite 6 losses, Missouri is a surprise #2 in the SEC and has looked strong recently, including a win over Florida.  Barring an unlikely loss to Indiana State, Creighton looks set to win the MVC.  Arizona, meanwhile, lost both Los Angeles games and is an increasingly distant 4th in the Pac-12, so this rating is a bit of a mystery.  This may be a case where the Prediction Machine is being influenced by strong halftime results.  It will be interesting to see how Arizona performs in the Pac-12 tournament.

Saturday Top Ten Predictions

Loyola Marymount @ #1 Gonzaga:  Gonzaga by 10
#3 Duke @ UNC: UNC by 3
#4 Kansas @ Baylor:  Kansas by 1
#17 Syracuse @ #5 Georgetown: Georgetown by 1
Clemson @ #6 Miami (FL): Miami by 6
#24 Notre Dame @ #8 Louisville:  Louisville by 8
#9 Kansas St @ #13 Oklahoma St: Oklahoma St by 4

Today's games feature a couple of mismatches between the AP's rankings and the PM's rankings, I'll be interested to see how they turn out!

Top Twenty (3/1)

Rank	Change	Team	Rating
1	+1	Indiana	131
2	-1	Florida	127
3	+1	Gonzaga	111
4	+1	Kansas	110
5	+2	Wisconsin	110
6	-3	Michigan	110
7	-1	Louisville	109
8	+1	Ohio St.	105
9	-1	Syracuse	103
10		Duke	100
11	+1	Oklahoma St.	96.6
12	-1	Michigan St.	96.2
13		Pittsburgh	94.5
14		Iowa	92.3
15	+3	Minnesota	91.4
16	-1	Saint Louis	89.8
17		Georgetown	89.7
18	-2	Kansas St.	88.9
19	NR	Virginia	87.6
20	NR	Iowa St.	87.6

Commentary 

It was a week of "upsets" in college basketball -- or was it?  The PM correctly predicted likely upsets of Indiana at Minnesota and Duke at Virginia.  The PM also predicted that Michigan at Penn State was likely to be a lot closer than most people expected -- although even the PM didn't think PSU could win!

People focus too much on outcomes and have a hard time objectively assessing team strength.  Going into the Indiana game, Minnesota had lost 8 out of 11 and was being described as a "collapse."  But take a look at those losses (showing the PM rankings of the opponents): 

1/12: @ #2 Indiana (-7)
1/17: vs. #3 Michigan (-8)
1/23: @ NR Northwestern (-7)
1/26: @ #7 Wisconsin (-1)
2/6: @ #11 MSU (-11)
2/10: vs. NR Illinois (-4)
2/17: @ #14 Iowa (-21)
2/20: @ #9 tOSU (-26)

The truth is, when you play teams that are better than you on the road, you're going to have a bad time :-)  To put this stretch in perspective, Duke/Kansas/Syracuse would all be expected to lose 6 of those games.

The only "bad" losses here are to Northwestern (but that was on the road) and to Illinois at home (but that was only by 4 points).  They did lose by 20+ to both Iowa and tOSU, but those teams are both better than Minnesota and were playing at home.  And in the same period they won at home against #14 Iowa and #7 Wisconsin.

Minnesota lost to Indiana by 7 at Indiana.  If we take a rough figure of 3.5 points for the Home Court Advantage, then we'd expect Indiana at Minnesota to be about a toss-up.  (The PM actually had Indiana as about a 2.5 point favorite based on other factors.)  So it really shouldn't be a surprise that Minnesota beat Indiana, and that probably shouldn't affect your assessment of either team that much.

The win over Duke (another not entirely unexpected result) was enough to pull Virginia up into the Top Twenty.  They should be a lock for the Tournament at this point, although they might need a few more solid wins to convince the Committee.

Saturday Picks

Iowa at #1 Indiana:  Indiana by 14
Portland at #2 Gonzaga: Gonzaga by 26
#5 Miami at #3 Duke: Duke by 9
WVU at #6 Kansas:  Kansas by 15
Rutgers at #7 Georgetown: Georgetown by 12
Alabama at #8 Florida: Florida by 15
#10 Louisville at #12 Syracuse:  Syracuse by 2

Most of the Top Ten teams are playing comfortable home games against mediocre opposition.  #5 Miami @ #3 Duke is being touted as the marquee matchup of the day, but it's likely to be a fairly routine Duke victory.  More interesting will be #10 Louisville @ #12 Syracuse, where Louisville will have a good chance (~40%) of pulling the upset.  Other good games outside of the Top Ten include Arizona at UCLA and Clemson at Virginia Tech, both of which are coin flips.

Top Twenty (2/22)

Ranking	Delta	Team	Rating
1		Florida	135
2		Indiana	133
3		Michigan	114
4	+3	Gonzaga	111
5	-1	Kansas	111
6	-1	Louisville	107
7	+2	Wisconsin	107
8		Syracuse	106
9	-3	Ohio St.	105
10	+1	Duke	101
11	+3	Michigan St.	96
12		Oklahoma St.	95.1
13	-3	Pittsburgh	94.9
14	+2	Iowa	93
15	NR	Saint Louis	90.4
16	NR	Kansas St.	89.5
17	+2	Georgetown	89.4
18	-5	Minnesota	89.4
19	-2	Miami (FL)	88.5

No change in the Top Three from last week, which surprises me a bit.  Indiana performed about as expected, while Florida over-performed against Auburn and under-performed against Missouri, with the result that they treaded water at the top of the rankings.  (Michigan State moved up in large part by outplaying Indiana in the 2nd half of the loss.)  The Billikens, who were hanging just off the bottom of the Top Twenty last week, vaulted all the way to #15 based on strong wins against Charlotte and VCU.  St. Louis gets Butler tonight in an important A-10 matchup.  The PM favors Butler by a mere 1.5, so it should be a good game. The biggest surprise move is KSU, vaulting upwards after wins over mediocres WVU and Baylor.

Still a big gap between Florida/Indiana and the rest of the field.  They could well meet up in the Championship game if they start in opposite halves of the bracket.

AP Top Ten Matchups this Saturday:

#2 Miami (FL) @ Wake Forest:  Miami by 7
San Diego @ #3 Gonzaga:  Gonzaga by 24
Arkansas @ #5 Florida: Florida by 17
#11 Georgetown @ #8 Syracuse:  Syracuse by 10
TCU @ #9 Kansas:  Kansas by 25
Seton Hall @ #10 Louisville:   Louisville by 17

It looks to be a day of blowouts, although the Miami game might be interesting.  Georgetown-Syracuse is being touted as the big matchup, but it's likely not going to be that competitive.  Syracuse is significantly better than Georgetown and playing at home, and the combination is likely too much for the Hoyas to overcome.

Prediction Review

How did the PM do this Saturday?

#1 Indiana by 19 over Purdue

Indiana actually won by 28.

#2 Duke by 5 over Maryland

• Gary Williams is gone, so don't expect one of his patented Maryland surprises.

Fear the Turtle!  Gary Williams' ghost (what, he isn't dead?) must have inspired the Terps, because they handed Duke a patented unpleasant surprise at what might be the last Duke-Maryland matchup at Comcast Center.

#5 Gonzaga by 12.5 over San Francisco

• Gonzaga on cruise control.

Gonzaga by 10

#6 Syracuse by 8 over Seton Hall

Syracuse by 11

#7 Florida by 16 over Auburn

• Florida remains amazingly under-ranked and Auburn is turrible.

The actual margin was 31.  Hopefully the AP voters will take notice.

#8 MSU by 9 over Nebraska

• Nebraska also turrible.

MSU by 9.

#10 KSU by 4 over Baylor

• A good chance for an upset in this game -- KSU is very over-ranked in the polls.

KSU by 20.  KSU controlled the second half and throttled Baylor in what is a very nice result for them.

So not a terrible day for the PM.  It missed one upset and got several games within one basket.

Predictions Check

#2 Florida by 25 over Mississippi State

Florida won by 25.


Wisconsin by 1.5 over #3 Michigan

Wisconsin isn't ranked but should be.  This game is at Wisconsin.

Wisconsin won by 3 in OT.  Did the PM call the correct winner in this game?  Ultimately, yes.  But you could argue that with the game tied at the end of regulation, the prediction was off by -1.5 points, instead of +1.5 points.

#5 Kansas by 6 over Oklahoma.
 
Oklahoma by 6.   Maybe I got the sign on the prediction wrong :-).  I didn't see any of the game, but not a good loss. 

#6 Gonzaga by 23 over Loyola-Marymount

Gonzaga is over-ranked at #6, but LMU is not good.

Gonzaga by 19.

 #8 Miami (FL) by 3 over UNC

This is basically a coin-flip game.  The polls will be expecting Miami to win and will punish them if they lose, but this would actually be a very solid win for them.

Miami won by 26 thanks to an onslaught of threes.  There's no way in a predictor to account for something like Miami hitting 15 of 26 threes.  Coach Larranaga (a personal favorite) is setting all sorts of records at Miami this season, including becoming the only team in the ACC outside of North Carolina to start the conference season 10-0, but talk of a #1 ranking is premature.  After Saturday's games, the PM has Miami at #17. (Sorry, Jay Bilas!) The ACC is weaker than usual this year, and I'm dubious that Miami is in the same class as Florida/Indiana/Michigan.  That said, I'm looking forward to seeing if Coach L can make some noise in the Tournament.

#11 Louisville by 5 over #25 Notre Dame

With 50 seconds to go, Louisville was up 5 on Notre Dame, and I tuned in to confirm the PM's prediction.  Then Jarrod Grant hit three straight threes and an old-fashioned three-point play to send the game to OT.  Five OTs (!) later, Notre Dame won by 3. The Prediction Machine can handle games up to 7OT -- I figured one more than the Syracuse-UConn marathon would be sufficient -- but I was a little worried last night that I would have to extend the code.

The treatment of OT games -- and particularly whether they should be treated as "ties" -- is interesting and I'll probably do a post on that soon.

Top Twenty (2/8)

Rank	Change	Team	Score
1	+1	Indiana	131
2	-1	Florida	130
3		Michigan	126
4	+1	Ohio St.	110
5	-1	Kansas	110
6	+2	Louisville	109
7		Syracuse	105
8	+4	Duke	105
9	-3	Gonzaga	104
10	+1	Pittsburgh	101
11	+2	Wisconsin	98.2
12	-2	Minnesota	97.8
13	+2	Arizona	93.7
14	+4	Oklahoma St.	92.3
15	-6	Creighton	90.2
16	+1	Iowa	90.1
17	-3	Cincinnati	89.6
18	-2	Kansas St.	88.7
19		VCU	87.4
20	+1	Michigan St.	86.7

Some shuffling of the deck chairs up at the top of the rankings, but thanks to the #1 teams swapping losses every week no one has really plummeted.  But absolute strength scores took a hit -- from 144 at the top last week to only 131 this week.  Duke (averaging +14 points over the last four games) and Oklahoma State (thanks to the win over #5 Kansas) both surge upwards, while Creighton plunges thanks to three losses in the last six games.

Predictions for Saturday's Top Ten games:

#2 Florida by 25 over Mississippi State
Wisconsin by 1.5 over #3 Michigan

Wisconsin isn't ranked but should be.  This game is at Wisconsin.

#5 Kansas by 6 over Oklahoma.
#6 Gonzaga by 23 over Loyola-Marymount

Gonzaga is over-ranked at #6, but LMU is not good.

 #8 Miami (FL) by 3 over UNC

This is basically a coin-flip game.  The polls will be expecting Miami to win and will punish them if they lose, but this would actually be a very solid win for them.

 #11 Louisville by 5 over #25 Notre Dame

Prediction Results

A follow-up to Saturday's predictions.  Individual results don't mean much, but it's fun to look at them once in a while:

#3 Indiana by 8 over #1 Michigan

The line on this game was surprisingly low (4.5) maybe because of partisan betting, or because people don't understand HCA.  Anyway, the PM was dead-on, and Indiana won by 8.

#2 Kansas by 9.5 over Oklahoma St.

Oklahoma St. by 5 - a bad loss for Kansas.

#4 Florida by 15 over #16 Ole Miss

Another good call by the PM: Florida by 14.  The PM I think rightly rates Florida much higher than the polls.

#5 Duke by 7 over Florida State

Duke by 19. 

Pittsburgh by 2.5 over #6 Syracuse

Pittsburgh by 10 -- the PM gets the "upset" correct.  This will be viewed as a bad loss for Syracuse, but really shouldn't have been surprising.

#7 Gonzaga by 18 over San Diego

 Gonzaga by 2, with a last-second shot required to avoid what would have been a big upset.

 #8 Arizona by 8 over Washington St

 Arizona by 14.

 #9 Butler by 15 over Rhode Island

 Butler by 7.  Not a good showing at home against 4-10 Rhode Island.

 #10 Oregon by 3 over California

 California by 4.

 #11 tOSU by 13 over Nebraska

 tOSU by 7.

 #19 NC State by 3 over #14 Miami (FL)

Miami (FL) by 1.  The PM almost calls what would have been a big upset.  (It did get the game right against the line, at least.)  Coach Larranaga is doing a nice job in his second year.

#15 Wichita State by 4 over UNI

UNI by 5.  A nice win for UNI, who has been inconsistent this season, but sometimes very good.

#17 Missouri by 19 over Auburn

Missouri by 14.  Close enough :-)

Oklahoma by 1/2 over #18 Kansas St

Kansas State by 2.  This looked to be the closest game in the Top Twenty and delivered.

#20 New Mexico by 13 over Nevada

New Mexico by 20.  The PM rounds out the Top Twenty with another bullseye.

So overall the PM went 10-5 and called 5 games within 5 points.

PM Top Twenty (2/1)

#	Move	Team	Score
1		Florida	144
2	+1	Indiana	132
3	+1	Michigan	130
4	-2	Kansas	124
5		Ohio St.	112
6	+3	Gonzaga	106
7	-1	Syracuse	106
8	-1	Louisville	105
9	-1	Creighton	102
10		Minnesota	100
11	+3	Pittsburgh	99.95
12	-1	Duke	99.3
13	-1	Wisconsin	98.1
14	-1	Cincinnati	95.1
15	+3	Arizona	93.4
16	+4	Kansas St.	91.8
17	-2	Iowa	89.7
18	-1	Oklahoma St.	89.1
19	-3	VCU	87.4
20	NR	N.C. State	85.9

Florida remains in the #1 spot this week, with 30 point wins this week over Mississippi State and South Carolina. A bigger test comes up on Saturday when they face Ole Miss. Ole Miss is #16 in the AP poll but has dropped to #44 in the PM's ratings, so it should be an routine win for Florida and the last week for Ole Miss in the AP Top Twenty.

The big winner this week is Kansas State, jumping four places even though they lost last Saturday to Iowa State.  They're benefiting from their great strength of schedule.  Pittsburgh, Arizona and Gonzaga make significant leaps with strong wins or good losses.  Pittsburgh is a good example of the latter -- losing to Louisville by only 3 at Louisville is a strong positive.

The big loser this week is VCU, tumbling three spots after a bad loss to La Salle at home.

Predictions for Saturday's Top Twenty-Five games:

#3 Indiana by 8 over #1 Michigan
#2 Kansas by 9.5 over Oklahoma St.
#4 Florida by 15 over #16 Ole Miss
#5 Duke by 7 over Florida State
Pittsburgh by 2.5 over #6 Syracuse
#7 Gonzaga by 18 over San Diego
#8 Arizona by 8 over Washington St
#9 Butler by 15 over Rhode Island
#10 Oregon by 3 over California
#11 tOSU by 13 over Nebraska
#19 NC State by 3 over #14 Miami (FL)
#15 Wichita State by 4 over UNI
#17 Missiouri by 19 over Auburn
Oklahoma by 1/2 over #18 Kansas St
#20 New Mexico by 13 over Nevada

The power of the home court is evident in the Indiana, Pittsburgh, and NC State games. 

Team to Team Variation in Predictions

The current version of the Prediction Machine averages about 11 points of error in predicting games, across all teams and all seasons.  I've speculated that there are some subsets of games where the error is significantly less -- for example, it might be the case that we can predict much more accurately when a good rebounding team plays a poor rebounding team.  However, my efforts to identify those subsets have been largely futile and there's some circumstantial evidence to suggest that no subsets exist -- primarily that a Support Vector Machine does no better than a Linear Regression at prediction.  (We would expect a SVM to do better in a data set with significant subsets.)

Last week I thought it would be interesting to look at what teams the PM has done the best at predicting this year and which ones the worst.  (For some reason, it's never occurred to me previously to look at this.)  So I gathered up all the predictions and results for this season and segmented them out by teams.  (Note: I'm only looking at the games after the first 1000 games of the season and not the last 100 in this sample.)

The overall best team is Idaho, which the PM has predicted with about 4.6 points of error.  The PM has gotten 5 of Idaho's games within 2 points.  It missed one game by 10 points, but that was by far the worst.
The overall worst team is Mississippi St with 18 points of error.  The PM missed games by 35, 29, 17, and 15 points.  So the overall range of predictions runs from less than 1/2 the average error to almost 2x the average.

 

I also took a look at the error for home games and away games separately.

Just looking at home games, the most predictable is TX Pan American (2.3 points error) and the worst Youngstown State (28.7 points error).  For away games only, the most predictable is Portland St (0.86 points error!) and the worst is Maryland (20.5 points error).   For Portland State's four away games, the PM was off by 0.7, 1.3, 0.4 and 0.7 points (!).  Maryland is a bit deceptive -- they only have two away games in the sample, and one was the Northwestern game which they were expected to lose by 9 and won by 20.

Some of this is no doubt just random variation.  Just by chance the PM will get some team's games close and some team's far off.  That effect should diminish the more games we sample, so I took a look at the entire 2012 season.

The overall best team to predict in 2012 was Dartmouth, with 6.3 points of error on average.  The worst was New Orleans, with 19.3 points of average error.  Once again we see a range of roughly 1/2 to 2x the average error.  The best home team to predict was Indiana St, at 4.7 points of error, and the worst Longwood at 17.15 points of error.  The best and worst away teams were Gardner-Webb (4.14) and New Orleans (22).   So again we see the overall range of predictions runs about 1/2 the average error to about 2x the average error.

Another test we can do is to look at how many teams that were predictable in the first half of the season are also predictable in the second half of the season.  If the effect is random, we'd expect to see a random level of overlap.  For the 2012 season, if we look at the most predictable half of the teams in both the first part of the season and the second part of the season, there's almost exactly 50% overlap -- a strong indication that the effect is just random variation.

The conclusion is that the error range on the PM's predictions for particular teams runs from about 1/2 the overall average to about 2 times the average, but that this variation is probably random.

Here are some results from Saturday's predictions:

Away	Home	Pred	Line	Actual	Pred vs. Line
#6 Syracuse	#1 Louisville	6.8	6.5	-2	Lose
#4 Kansas	Texas	-10	-10	5	Push
#7 Arizona	ASU	-6	-7	17	Win
#8 Gonzaga	#13 Butler	-4	-3	2	Lose
#17 Missouri	#10 Florida	9	13	31	Lose
#11 OSU	#18 MSU	-1	2.5	3	Lose
#12 Creighton	WSU	1	2.5	3	Lose
#15 SDSU	Wyoming	5.5	-1.5	13	Win
Oklahoma	#16 KSU	6	6	9	Push
#21 Oregon	#24 UCLA	2		-9
#22 VCU	Duquesne	-13	-14.5	-27	Lose
#25 Marquette	Cincy	4		3 (OT)
E Illinois	Austin Peay	0	5	-10	Win
E Kentucky	Jacksonville St	0		-11
Miami (OH)	E Michigan	0	1.5	7	Lose

A couple of notes.

The PM's prediction is often very close to the line for the game.  There are few games where it differs by more than a few points.  In this set of games, the Florida game, the Wyoming game and the Austin Peay game stand out with more than 4 points difference with the line.  This suggests that Vegas uses very similar technology to help set the lines.

It's interesting to note that the three games the PM thought would be close weren't particularly.

The PM didn't do particularly well on this set of games, although it did win 2 out of 3 where it differed significantly from the line.  In 3 games where it differed on the winner with the line, the PM also won 2 out of 3.  Neither result is significant, but the PM does slightly outperform the line in general.  The PM "bets" on games that meet certain criteria, including a significant point difference from the line.  Of these games, two met all the criteria:  the Austin Peay game and the Wyoming game, both of which the PM won.  Eight games total met all the criteria on Saturday, and the PM "won" five of those games.  For the year, the PM is 55% against the line for games that meet all the criteria.

Here are some predictions for today's games from the Prediction Machine (PM):

#6 Syracuse @ #1 Louisville:  Louisville by 6.

Syracuse is not good enough to beat Louisville at home.  The return game on 3/2 could be more interesting.

#4 Kansas @ Texas:  Kansas by 10.5

Texas just not a good team this year.

#7 Arizona @ ASU:  Arizona by 6.

ASU has lost to all the decent teams they've played, but might be good enough to surprise someone one of these days.  Maybe Arizona?  Maybe UCLA?

#8 Gonzaga @ #13 Butler: Gonzaga by 4

Should be a good game.

#17 Missouri @ #10 Florida: Florida by 9

Florida is probably under-ranked right now.

#11 OSU @ #18 MSU:  OSU by 1

Basically a toss-up.  The Big Ten looks tight this year, so could end up being an important game.

#12 Creighton @ Wichita State:  Wichita State by 1

Creighton seems be a dark-horse darling for a lot of analysts, but the PM isn't impressed (yet).

#15 SDSU @ Wyoming: Wyoming by 5.5

Wyoming screwed the PM the other night by losing by 13 on the road to Fresno State, but the PM is doubling down on a big home win.  We'll see.

Oklahoma @ #16 KSU: KSU by 6.
Rutgers @ #20 NDU: NDU by 9.5

Should be routine wins for both home teams.

#21 Oregon @ #24 UCLA: UCLA by 2

Basically a toss-up.

#22 VCU @ Duquesne: VCU by 13

VCU is another analyst darling and will not be challenged by Duquesne.

#25 Marquette @ Cincy: Cincy by 4

Unless a fight breaks out.

Other Interesting Games:

   Maryland @ UNC: UNC by 7.  (I would have thought this would be closer.)

   Kentucky @ Auburn: UK by 9.  (Surprised it's not more.)

Blowouts:

  Nicholls @ Stephen F. Austin:  Austin by 39
  Portland @ St. Mary's: Portland by 13

Nailbiters:

  Eastern Illinois @ Austin Peay:  Austin by 0.06
  Eastern Kentucky @ Jacksonville St.: Jacksonville by 0.08
  Miami (OH) @ Eastern Michigan:  Eastern Michigan by 0.09

For some reason the Eastern schools are playing tight today.

Made some interesting progress this week on some aspects of the predictor, and I hope to report out on them soon.

Prediction Season

Please pardon the unintentionally long hiatus.  The holiday season, a trip, and some program problems have interfered with my regularly scheduled prophecy.

It takes about 1000 games before my predictor settles down to reliable predictions.  This usually occurs around the start of January.  Two problems interfered with that this year.  First, I started scraping game results from ESPN this year (Yahoo has gotten somewhat unreliable) and only discovered around the beginning of January that I wasn't getting all the games.  It took a few days to fix that problem.  Then I ran some tests and found my predictions were way off.  Tracking down the cause took another week or so.  The exact problem was complex, but it had to do with determining the length of games.  (For pace-adjusted statistics you need to know the number of minutes played.)  Once that was fixed the predictor started behaving as expected.

So here are some predictions for tonight's games, starting with the ranked teams:

  #1 Louisville (15-1) @ Connecticut (12-3): Louisville by 8
  Baylor (11-4) @ #4 Kansas (14-1) : Kansas by 8

Connecticut is probably under the radar right now -- they've got good wins over MSU and Notre Dame, and their loss to NC State looks better after NC State's win over Duke.

Most competitive games of the night:

   Elon (8-7) @ Western Carolina (7-9): Elon by .2
   Savannah St. (7-9) @ Morgan State (4-8):  Morgan State by .5

Blowouts of the night:

  Grambling St. (0-14) @ Texas Southern (4-13):  Texas Southern by 25
  Charleston (11-5) @ Citadel (3-11): Charleston by 13

It's amazing that a 4-13 team can be a 25 point favorite in a game, but Grambling is really bad and has a good chance of going winless for the season.

As usual, these predictions are provided for your reading pleasure only.  A full disclaimer can be found in the sidebar.

3PT Attempt Percentage

Ken Pomeroy recently made a couple of blog postings concerning defense, and specifically a statistic he calls the "3 Point Attempt Percentage" (3PA%).  He defines this statistic as the "percentage of field-goal attempts that are from three-point range."  Ken Pomeroy thinks this is a better measure of defense than 3PT%.  His reasoning is that most teams only take 3 point shots when they are relatively unguarded; the effect of defense is not to make these shots harder, but to cut down on the number of opportunities.  Hence the claim that it's really how many 3 pointers your opponent takes that reveals the quality of your 3PT defense.  Near the end of the second posting he says:

People that are unaware of 3PA% (which is to say nearly everyone) are missing a very telling statistic that explains a lot of how defense works.

This is a strong statement and worthy of a little research to see whether it is true (at least so far as predicting outcomes is concerned).

3PA% is similar to Effective Field Goal Percentage, one of Dean Oliver's Four Factors.  I have previously considered the Four Factors and concluded that they didn't add any predictive value to my models, but 3PA% captures a slightly different slice of information.

When I recently looked at derived statistics, one of the derived statistics was pretty close to 3PA%:

(Ave. number of 3PT attempts by the opposing team)
------------------------------------------------------
(Ave. number of FG attempts by the opposing team)

This isn't quite the same statistic, because it is using game averages rather than cumulatives, but it is close.  This statistic turned out to have no predictive value, but a couple of statistics based upon 3PT attempts did have value:

(Ave. number of 3PT attempts by the opposing team)
-----------------------------------------------------
               (Ave. number of turnovers)

(Ave. number of 3PT attempts by the opposing team)
-----------------------------------------------------
               (Ave. number of rebounds)

Note that these statistics are relating the number of 3PT attempts by the opponent to a statistic for the defending team.  I'm not entirely sure what these statistics are capturing, but I don't think it is 3PT defense.  (The latter might be indirectly saying something about how a team defends against the three pointer, from how it is positioned to rebound effectively or not after a taken three pointer.)

That aside, I modified my models to generate four new statistics:  the 3PA% for the home team in previous games, the 3PA% for the away team in previous games, the 3PA% for the home team's opponents in previous games, and the 3PA% for the away team's opponents in previous games.  I then tested the model both with and without these statistics:

Model	Error	%Correct
Base Statistical model	11.06	72.7%
Base Statistical model + 3PA% statistics	11.05	72.7%

There's a very small improvement in RMSE with the added 3PA% statistics.  So at least for my model, the 3PA% statistics don't seem to add any significant new information.

Football Wrap-Up

A quick wrap-up of my performance predicting NCAA football.

This experiment started around the beginning of October, when some friends challenged me to use my program to predict football against a couple of other guys.  In addition to predicting games, we would be "betting" against the line.  We could use any betting strategy we desired to allocate $40 per week.  The default strategy was to bet the biggest differences between the prediction and the line, allocating bets of $10, $8, $6... etc.  My own betting strategy was a bit more complex.  I allocated money according to the formula:

$$ =  80*ABS(Prediction-Line)/(100+5*ABS(Line)))

.The idea being to scale the bet to the relative magnitude of the difference between the prediction and the line.  A difference of 3 points is much more significant when the line is 3 than when the line is 27.

I predicted games from Oct 16 through the end of the bowl season.  My program doesn't account for neutral site games, so the bowl games were treated as home games for the higher-ranked team.  (This works well in practice on the basketball side for the NCAA tournament.)  I predicted a total of 224 games.  The results:

Measure	Performance
Correct game winner	73%
Correct pick against the line	56%
Betting result	+$29

Overall, better results than I expected.  56% against the line is sufficient to be a winning bettor (if it can be maintained).

Football Predictions (11/15/11)

I hope to have some time in the next day or so for some postings, so here are the predictions for this week in NCAA football.  I've been tracking this performance for a contest, and for the past three weeks I'm 56% against the line (and 71% winners).  That might be anomalously good performance, but I've been positive against the line every week, so take that for what it is worth.

As always, heed the Net Prophet Disclaimer.

NCAA Football Predictions (11/15/11)

Home Team	Away Team	MOV
Air Force	Nevada-Las Vegas	16.1
Arizona State	Arizona	18
Arkansas	Mississippi State	13.1
Baylor	Oklahoma	-14.2
Bowling Green State	Ohio	-6.7
Brigham Young	New Mexico State	15.7
Buffalo	Akron	12.3
Central Michigan	Toledo	-14.9
Connecticut	Louisville	0.4
Duke	Georgia Tech	-6.9
East Carolina	Central Florida	-8
Florida State	Virginia	16.8
Georgia	Kentucky	24.5
Hawaii	Fresno State	9
Houston	Southern Methodist	18.3
Idaho	Utah State	-8.3
Illinois	Wisconsin	-9.9
Iowa State	Oklahoma State	-17
Kent	Eastern Michigan	6
Louisiana-Monroe	Florida International	-3.3
Memphis	Marshall	-15.4
Miami (Ohio)	Western Michigan	-2.4
Michigan	Nebraska	10.2
Michigan State	Indiana	20.9
Middle Tennessee State	Arkansas State	-11.5
Mississippi	Louisiana State	-26.3
Missouri	Texas Tech	15.2
Nevada	Louisiana Tech	1.8
North Carolina State	Clemson	-9.1
North Texas	Western Kentucky	2
Northern Illinois	Ball State	11.5
Northwestern	Minnesota	14.3
Notre Dame	Boston College	22.3
Ohio State	Penn State	1
Oregon	Southern California	14.9
Oregon State	Washington	-0.4
Purdue	Iowa	-1.6
Rice	Tulane	15
Rutgers	Cincinnati	0.8
San Diego State	Boise State	-13.6
San Jose State	Navy	-1.8
South Florida	Miami (Florida)	3.9
Stanford	California	20.3
Temple	Army	15.8
Tennessee	Vanderbilt	2.6
Texas	Kansas State	3
Texas A&M	Kansas	23.8
Texas Christian	Colorado State	24.4
Texas-El Paso	Tulsa	-10.4
Troy	Florida Atlantic	11.2
Uab	Southern Mississippi	-26.2
Ucla	Colorado	12.2
Virginia Tech	North Carolina	6
Wake Forest	Maryland	11.1
Washington State	Utah	-2.4
Wyoming	New Mexico	20.4