In 1961, the AP decided to reduce the number of teams appearing in their weekly football rankings from 20 down to 10. That continued through the 1967 season before they switched back to 20 teams in 1968.
For many years it has been widely accepted that the final poll of the 1961 season actually ranked 20 teams making it the only one out of 86 during that seven year period to do so. It's always been a head-scratcher, but I never bothered to look into it any further.
In September 2018 I was contacted by a researcher pointing out this anomaly and making the case that it should only be 10 teams. After a brief dive into some newspaper archives, I agreed with him and updated the poll and all the appearance streaks for the teams ranked #11 to #20.
In May 2021 I was contacted by another researcher asking why there were only 10 teams ranked. I retraced my steps from 2018 as much as I could, but I had to go back to the newspapers again to give an adequate response. So, to hopefully shed more light on this issue, here are my findings.
It is likely that the 20-team poll came from one or a combination of three sources: The New York Times archive, the book "Football Rankings: College Teams in the Associated Press Poll, 1936-1984" by Lowell R. Greunke, or the NCAA Records Book. Of these, the New York Times should be the go-to source since it was published at the actual time of the poll, not decades later. However, for this particular poll they happen to be the outlier.
As you can see in the article from the New York Times, it does not have a byline or dateline (may have been removed?), although the main text is very similar to the AP-branded wire story found in other newspapers. Additionally, they only have 19 teams ranked. If this was the original source for the others that followed, they obviously made the assumption that Duke was accidentally left out and added them at #20.
Greunke's book was published in 1984. It is lesser known than the other two, but some of the researchers I've been in contact with over the years have heard of it if not actually own it themselves. In fact, it's the primary source that I used to get started back in 2001.
In my only communication with Greunke back in 2008, I asked about his sources. This was part of his reply:
"I started with the Omaha World-Herald and New York Times on microfilm at the Omaha Public Library and for those I could not find I borrowed microfilm for the Chicago Tribune, Los Angeles Times, etc. from large public libraries around the country. At the end, I think I even had to ask the Associated Press headquarters for help on a couple rankings."
Given the other information to this point, his mention of the New York Times raises a flag. Not surprisingly, the email address I used to contact him back then is no longer active, and I did not find him on Facebook or Twitter. So at this time I can't confirm if that's the article he used as the source for this poll.
Note: I tried looking in the Chicago Tribune and Los Angeles Times archives, but could not find the final poll in either one.
The NCAA Records Book dates back to at least the 1950s, but the earliest I have access to is 2001. It has included a "National Poll Rankings" section ever since that edition. They have 20 teams ranked for this poll in the "Associated Press (Writers and Broadcasters) Final Polls" subsection in each edition. Based on what I found on eBay, it appears they first added that section in 1999. So I'm assuming they had the same data for this poll in both the 1999 and 2000 editions.
To investigate this issue back in 2018 and again in 2021, I primarily used Newspapers.com. If there is a single source in this case, it will be the AP wire story published in 1961.
In their archive, I found articles like this one with the same story published between December 5th and 7th, 1961. Sometimes the text of the main article is slightly different, but the actual poll itself is the same: 10 teams ranked (some include the Others Receiving Votes, some don't). After finding almost 30 of these on just the first two pages of search results, I stopped looking. But that repetition is expected given the nature of a wire service like the AP, UPI, etc.
Note: I did find a copy of the poll from the Omaha World-Herald and it matched the others found on Newspapers.com. That surprised me given what Greunke had told me in his email.
In addition to the actual poll itself, I found a few other articles that had the chance to mention a ranking for teams oustide the Top 10, but didn't. Most notable is this article by AP sports writer Will Grimsley in which he gives an overview of the four January 1, 1962 bowl games including the rankings for each team. The Orange, Sugar, and Cotton bowls all featured Top 10 matchups. However, the Rose Bowl teams were listed as "Minnesota, No. 7, vs. UCLA, unranked" (UCLA is ranked #16 in the sources with a Top 20).
Barring something really unusual being found, I think the answer to this is pretty obvious. By sticking with the original wire story, you don't have to do a lot of back-bending to explain the 19 teams ranked in the New York Times, or 20 in other publications from the last 20 years or so when there's no consistent evidence from 1961. It just seems more likely that this was a mistake that was propagated over the last few decades, which is something I have run into before in other research.
I have contacted some of the prominent players involved in this to try and find out what their sources were. It's probably a longshot given how long ago it has been and the low priority of this issue, but if they respond I will provide an update here.
August 2021: Sports Reference could not find where the 20 teams came from either.They concurred with this research and have updated their website.
If you have a newspaper clipping of this AP poll from a different source that shows 20 teams ranked, or have some other insight into this issue, please contact me.