Overvaluing Previous Year’s Success in Preseason Rankings

Posted by William Ezekowitz on November 20th, 2015

Part of what makes college basketball both exciting and maddening is that each year we have to throw out the previous year’s assumptions and start from scratch. If that wasn’t apparent before this season started, it became painfully obvious when mighty Wisconsin, last year’s national runner-up, lost to Western Illinois, the worst team in last year’s Summit Conference. But perhaps it is the case that we don’t erase the previous year from our memory at the beginning of each season as much as we should. The Badgers, despite retaining just three of the eight players who earned meaningful minutes and bringing in zero top 100 recruits, were still ranked 17th in the preseason polls. In fact, 13 of last year’s Sweet Sixteen teams started the season in the USA Today Preseason Top 25. Can the success of all of these programs be so stable? Or are we perhaps suffering from recency bias, where we tend to overvalue teams that have recently succeeded, even if the personnel structures of those teams have drastically changed?

Wisconsin made the Final Four last year, and look to return.

Wisconsin is a Possible Example of Recency Bias in Polls. 

In order to answer this question, I checked the preseason and postseason USA Today Coaches’ Polls (with postseason being taken after the conclusion of the NCAA Tournament), and checked how many Sweet Sixteen teams from the previous season were in each poll. If we are overvaluing Sweet Sixteen teams, then there would consistently be more teams from the previous year’s Sweet Sixteen in the preseason poll than in the postseason poll, which would indicate that Sweet Sixteen teams have dropped out due to poor performance.

This is exactly what has happened. Going back seven years, the number of previous year’s Sweet Sixteen teams has always been greater in the preseason poll than in the postseason poll. Of 112 possible Sweet Sixteen teams to choose from in those seven years, 77 have appeared in the preseason poll and just 61 have appeared in the postseason poll. A difference of proportions test reveals that these two numbers are significantly different from each other at the 95 percent confidence level, which, in layman’s terms, means that this trend is too strong to write off as pure coincidence.

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Morning Five: 08.29.13 Edition

Posted by rtmsf on August 29th, 2013

morning5

  1. It’s not very often that a piece of random news floors us, but the revelation that former Washington State, Iowa and USC head coach George Raveling has in his possession a copy of one of Martin Luther King’s original “I Have a Dream” speeches is nothing short of astonishing. CBS News reported on Tuesday that the 76-year old coach and media personality — then an assistant coach at Villanova — was one of the volunteer security marshals standing on the Mall near King 50 years ago when he delivered his rousing speech, and that King handed him a copy of it as he stepped off the podium. One expert on genuine historical documents estimated that Raveling’s copy could be worth as much as $20-25 million on the open market, given that King’s most famous speech was given at the height of the civil rights movement. It is sometimes so beautifully strange how life intersects with itself.
  2. And on that note, we move to eligibility issues. The NCAA ruled Wednesday on the case of former Louisville and Florida International forward Rakeem Buckles, a fifth-year senior who had applied for a transfer waiver (based on FIU’s postseason ban) to play at Minnesota this season. If his appeal is denied, Buckles will be forced into a precarious situation where if he stays at Minnesota he risks gambling that the NCAA will allow him a sixth year of eligibility in 2014-15 (no slam dunk), or he will have to return to FIU this season to play in a no-win situation there. For Minnesota, a team facing a significant rebuilding project inside after losing most of its frontcourt talent, Buckles was expected to help man the interior for new head coach Richard Pitino. Now all he can do is cross his fingers and hope for the best.
  3. We mentioned the Lindy’s top 10 rankings in yesterday’s M5, and that created a bit of a firestorm on Twitter as a result. But the truth is that in today’s college basketball environment there are no teams in any year that don’t come in with weaknesses. The most experienced teams are short on talent; and the most talented teams are short on experience. As a result, your preseason top 10 might look a good bit different than ours, and even splitting the difference, there’s a better than reasonable chance that both of us will be completely wrong. The Sporting News yesterday released its 16 regional magazine covers, in the process also unveiling its preseason top 10, and needless to say, there were fewer surprises than with Lindy’s. Mike DeCourcy took time to break down each team’s glaring weakness, and as we’ve said before, even using the dreaded slideshow format, he gives great analysis that makes it worth the click-throughs. Although we’re still not sold on North Carolina, fellas, just for the record.
  4. One of the teams we do believe in next season is Duke, and it goes without saying that Mike Krzyzewski will mold his personnel into a tightly-knit unit that maximizes the talent it can put on the floor. One of K’s all-time great point guards — and there have been several — was Bobby Hurley, and as the standard by which most of the others are measured, he is about to begin his first season as a Division I head coach at the University of Buffalo. ESPN.com‘s Dana O’Neil writes that Hurley the head coach is truthfully in no hurry to get his young charges started on their first season with him at the helm — in fact, he wants as much time as possible to set goals and expectations. Of course, there’s no telling whether the superb floor game and team leadership that Hurley possessed in spades at Duke can effectively translate to players two decades later who have barely heard of him, but if there’s any of the brand-new coaches we’d be willing on betting on, it would probably be this one. The guy has always been a winner.
  5. Where is Canada? We feel like there’s a South Park reference in that question somewhere, but that didn’t stop Wisconsin’s Sam Dekker from doing an ad lib Jaywalking-style Q&A with his teammates about all things above the border. It’s more cute than clever, but we will give it up for the #goodjobgoodeffort of somehow bringing Ryan Gosling into the mix.  But that’s enough from us, enjoy your Thursday, the starting date of the college football season, and feel free to start it off with the video.

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Preseason Polls Released Today

Posted by rtmsf on October 29th, 2009

seasonpreview

One of the favorite days of the year for us at RTC is when the preseason polls are announced.  Maybe it takes us back to our days growing up and anticipating the start of the season, but somehow, it just seems to make everything official.  Granted, media has changed a LOT since those days, and we spend more time nitpicking and disagreeing with these polls than we used to, but it’s still a cool harbinger that the season is just around the corner, so enjoy. 

Our QnD analysis follows the polls.

09 preseason polls v.2

QnD Analysis.

  • It’s clear the media thinks a little more highly of John Calipari’s Kentucky team and a little less than Roy Williams’ UNC team than the coaches do.  UK got 82.5% as many votes as Kansas in the coaches’ poll, while garnering 85.1% in the AP; meanwhile, UNC earned 84.8% in the coaches’ vs. 81.9% in the AP.  This is probably a good example that shows how coaches think versus how the media thinks.  It’s our view that coaches do not respect John Calipari as much as they probably should, so he gets dinged a little despite having A-list talent while Roy Williams gets a bump despite losing four starters.  On the other side, the media sees the players that Calipari has at his disposal this year and they get all googly-eyed thinking about it, so they tend to rate Kentucky higher than UNC, somewhat ignoring the history that Roy Williams has in getting teams to come together.  It’s a very subtle point, but we think a clear one.   
  • The team with the biggest disparity between polls, Minnesota, also illustrates this point beautifully.   Coaches rank Tubby Smith’s team #18 (19.5%) in the nation based on Smith’s reputation for overachieving; the media, however, doesn’t see as much talent on the court as some of the other teams around Minnesota, so while recognizing Tubby’s ability to get the most from his players, they rate the Gophers lower at #25 (10.6%). 
  • Louisville is also a strange case here.  The coaches rate the Cardinals quite a bit lower than the media does (#23, 15.9% vs. #19, 20.6%), and you wonder if they sense that all the bad news has taken a toll on the UL program and will manifest itself as a weaker team this year. 
  • Nice to see Butler getting nearly top-ten love as the best mid, but they’re going to have to earn that ranking very early in their schedule, with games at Northwestern, at Evansville, vs. Ohio St. and Xavier at home, plus neutral site games in the loaded 76 Classic in Anaheim and against Georgetown in MSG. 
  • In the ORV, Maryland will probably hover around the 20-30 zone all season, but what is going on with the coaches giving 22 votes to USC?!?!?  At first, we thought it was an abbreviation for “South Carolina” until we saw the other SC down at the bottom with a ridiculous one vote.  They do realize that Tim Floyd and OJ Mayo are no longer there, right?
  • No major qualms with the rest of it, although UCLA right now is a reach for the top 30 (too many unknowns) and Vanderbilt is going to be better than several teams in the top 25 this year. 
  • Conference Breakdown (Coaches, AP):  ACC (4, 4), A10 (1, 1), Big East (6, 5), Big 12 (3, 3), Big 10 (5, 6), Horizon (1, 1), Pac-10 (2, 2), SEC (3, 3).
  • Final thought – the RTC Preseason Top 25 will release on Opening Night (Monday, Nov. 9), so keep an eye out for that. 

What say you, readers?

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How Accurate are Preseason Polls?

Posted by rtmsf on November 14th, 2008

A question that’s befuddled us for a long time now has been just how accurate are all these preseason polls that every media entity puts out each year are.  Remember last season – all four NCAA #1 seeds made it to the Final Four, but what was equally interesting to us was that those same four teams – Kansas, Memphis, UCLA and UNC – were also the top four ranked teams (in a different order) in both the Preseason AP and ESPN Coaches polls.  With an n=1, we know that the 2007-08 polls were extremely accurate in predicting last year’s F4 teams, but that only tells us part of the story – what we really want to know is how accurate are preseason polls in general?

polling

To try to answer this question, we had to make some concessions.  We believe that, generally speaking, most preseason polls are largely the same, whether AP, ESPN/Coaches, CNNSI, etc.  Take for example, the blogpoll that came out this week.  The top twenty teams that the bloggers chose were mostly consensus picks – no team was left off of more than one ballot, and a total of only thirty-six teams received at least one vote.  That shows a relatively high consistency of thought – groupthink, if you will – about who the best teams in the country will be this season.  So we feel that we can derive some strong basic principles (and save a boatload of time) by examining only one of the major preseason polls – the ESPN/Coaches Poll – because it is the sole major poll that does a postseason version (after the NCAAs) to enable a fair comparison. 

We looked at the last five years where we could find the available pre- and postseason polls (the 2005 postseason poll is incorrect on both the ESPN and USA Today websites), and made some simple comparisons.  Our findings are below the table. 

preseason-coaches-poll-analysis

Findings.

  • In a given year, there are between 50-60 teams receiving votes from the preseason pollsters.  This tightens up to approximately 40 teams receiving votes in the postseason poll. 
  • So how does a team receiving preseason votes equate to the postseason?  Ehhh, not terrible, but not great either.  Over the last six seasons (excl. 2005), if a team received votes in the preseason poll, there was a slightly better than half (54%) chance that it would also get votes in the postseason poll.  That alone doesn’t tell us a whole lot, though.  What if your team was in the preseason Top 25?  Those teams receive votes in the final poll approximately three-quarters (76%) of the time, which at minimum, means that the takeaway is that a preseason team receiving votes will usually make the NCAA Tournament
  • Looking at the distribution of the final postseason polls can tell us a little bit about how accurate preseason pollsters are at predicting how good a team will be.  There appears to be a much stronger tendency to overlook teams that turn out later to be good rather than to overrate teams that turn out to not as good as pollsters thought.  Over half of the teams in a given year (~23) in the final postseason poll will have moved up >5 spots in the rankings from their initial selection; but only a handful of teams (~7) will have moved down by >5 spots from the preseason.  Another ~12 teams won’t move much from its initial standing.  This is strong evidence that pollsters generally have an accurate sense of the abilities of about 30% of teams in a given year, but they’re far more likely to underrate teams (usually by not ranking them at all) than to overrate teams (by a 3:1 ratio). 
  • Some of the more notable examples of the pollsters being right on the money were in 2004, when they rated UConn/Duke as #1/#2, which is exactly where they ended the season.  Florida rated as preseason #1 in 2007 and Kansas as preseason #2 in 2003 were some other clear winners. 
  • The swing-and-a-misses where the pollsters vastly overrated a team were Indiana in 2008 (#9 to #33), Duke in 2007 (#11 to #38), and Michigan St. in both 2006 (#5 to #34) and 2005 (#3 to #41).   
  • The biggest misses where pollsters underrated a team was most obvious in 2003 and 2007, when preseason #31 Syracuse and #39 Florida, respectively, vaulted all the way to #1 by season’s end, and in 2004 when preseason unranked Georgia Tech made it to the F4 and #3 at the end of the year.  The only other preseason unranked team to have made the F4 in the last six years was George Mason in 2006. 

What does this mean for the 2008-09 season?  Well, if your team was ranked in the Top 25, you’re more than likely going to make the NCAA Tournament.  And if you’re already highly ranked, you should feel relatively secure in your position at or near the top – most teams simply don’t have huge drops in rankings from beginning to end of the season.  The good news is that if your team was lower ranked or not ranked at all, but you feel like they’re extremely underrated, history shows that an awful lot of teams move significantly up the rankings as the season goes along.  We’ll leave the guesswork as to who those teams might be to the rest of you guys. 

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11.14.08 Fast Breaks

Posted by rtmsf on November 14th, 2008

Well, if we can get our ESPN Full Court package to work tonight, we might actually get to watch some games…  don’t hold your breath on Comcast actually coming through at the casa de RTC, though… 

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Preseason Polls Released

Posted by rtmsf on October 31st, 2008

Prediction:  by the end of the first week of December, UNC will no longer be #1 in the major media polls.

No way, there’s too much pressure and they have too many good teams to handle before we even get our advent calendars.  Oh, and did you hear, a small piece of their offense will be out for a while with a stress reaction?  Even if this substantial piece never misses a game, which is extremely unlikely, he’s going to miss practice and be out of ‘game shape’ for a while.  And no, we’re not talking about Marcus Ginyard, but his loss hurts too.

Here’s Carolina’s early schedule – you tell us how they’re going to come out of this unscathed…

  • v. Penn  (11.15.08) – easy enough at home, right?
  • v. Kentucky (11.18.08) – this home game suddenly becomes extremely interesting if TH is out or still ailing – Patrick Patterson will wipe up the inside.
  • @ UCSB  (11.21.08) – UNC fans will remember the west coast stopover game before Maui in 2004-05 well.  Trap game.
  • @ Chaminade  (11.24.08) – Maui Invitational first round – easy W.
  • v.  Alabama (probably) (11.25.08) – UNC should be careful to not sleep on an athletic Bama team, but will probably win regardless.
  • v. Notre Dame/Texas (probably) (11.26.08) – either of these teams could defeat a less-than-full-strength UNC in Maui.
  • v. UNC-Asheville  (11.30.08) – easy home win.
  • @ Michigan St. (Detroit) (12.03.08) – 40,000 people could watch this game at Ford Field, and UNC will absolutely need to be at full strength to win this game vs. MSU.

There are at least three opportunities for the major upset here, and if Hansbrough and/or Ginyard are out for any of those games, go ahead and mark it down.  UNC will not enter the second week of December #1 and unbeaten.

Now, on to the polls, where UNC was a unanimous #1 in the AP Poll for the first time EVER (nope, not even 1991 UNLV, 1992 Duke or 2007 Florida), and also unanimous in the Coach’s Poll.  No pressure or anything…  FYI – UNC has been preseason #1 six times in its history (incl. this year) – the results of those seasons are: 1982 (Natl. Champs), 1984 (S16), 1987 (E8), 1994 (R32), 2008 (F4) – all that’s missing is a first-round loss or a title game loss.

Here are the polls.

We plan on doing some broader-based analytics of preseason polls in a general sense next week, but for now, here are a few things that we noticed right away.

  • Biggest jumps from AP to Coaches – Georgetown (+4) and Duke (+3)
  • Biggest drops from AP to Coaches – USC (-3) and Wake Forest (-3)
  • Coaches tend to vote by available talent + belief in other coaches’ abilities – what does this say about Tim Floyd and Dino Gaudio in relation to JT3 and Coach K?
  • Overrated – UConn, Duke, Oklahoma, USC
  • Underrated – Wisconsin, Florida, Georgetown, Gonzaga
  • All 25 teams in both polls are duplicates, but it’s interesting that Xavier was #26 in the AP vs. #30 in the Coaches.
  • We’re a little surprised to not see St. Mary’s and Baylor ranked over teams like Villanova and Kansas, but whatever, that’s their poll, not ours.
  • Alabama gets 16 AP votes but a donut in the Coaches – Mark Gottfried, much?  And LSU is getting too much love for simply getting a new coach.
  • Conference Breakdown – Big East (7 + 2 others receiving votes); ACC (4), Big 10 (3), Big 12 (3), Pac-10 (3), SEC (2), CUSA (1), SoCon (1), WCC (1).
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