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AFL versus NFL: introduction

Posted by Jason Lisk on March 3, 2009

Next football season will mark the fiftieth since the American Football League began playing in 1960. With that historic anniversary approaching, I thought it would be interesting to take a look back and do an in-depth comparison of the teams in both leagues during the decade between the start of the AFL and the AFL-NFL merger for the 1970 season.

Ask someone who was around during this time how the AFL and NFL compared to each other, and you are likely to get a variety of answers, primarily dependent on where their allegiances lay. I hope to sort through this and provide a detailed statistical look that tries to bring all the available evidence to the table, put it in context, and try to develop a best estimate that answers both general and specific questions about the teams and leagues, and how they compared before 1970. This all may very well prove to be a fool’s errand, and but some of the types of questions which hopefully can be addressed include:

**When did the AFL catch up with the NFL during the 1960’s and become at least comparable competitors, if ever? Think of it in terms of kind versus degree. To draw a college football analogy, when did the AFL stop being the MAC to the NFL’s Big Ten—where a few teams may be able to be competitive but the rank and file would have trouble—and instead become the Pac-10, where one league or the other may have a better year at any given moment, but where we consider the talent roughly equal over time?

This is an important question for several of our historical rankings, like what Chase did here with wide receivers, as well as things like comparing Hall of Famers’ career numbers and awards across leagues, or evaluating career value, like Doug did with his Approximate Value system. We don’t generally adjust Tony Dorsett’s numbers in 1979 because he played in the weaker conference that year. When do we adjust, and not adjust, the numbers produced in the AFL?

**How much do the first four AFL-NFL Championship games really tell us about the relative strengths of the two leagues over each of those seasons, as well as the seasons prior to 1966? How big of an upset was the Jets over the Colts in 1968? How much did the AFL really improve from 1966, when the Chiefs lost SB I by 25 points, to 1969, when the Chiefs won by 16 points?

**How did the 1964 (insert AFL team) compare to the 1964 (insert NFL team)? How did a league average team in each league compare in every season in that decade? Who were the best teams and worst teams in each season, and for the entire decade?

That’s just a sample of the types of things I hope to answer. Of course, those kinds of questions would be reasonably difficult to answer precisely, even if we had lots of direct and relevant evidence, such as teams that played games that are inter-related to each other within the same season, much like schedules nowadays. But we simply don’t have that for the period, because the only non-exhibition games that the two leagues played head to head during this decade were the four championship games from January 1967-1970.

So my strategy is to look at a variety of evidence. Each type of evidence, taken by itself, has issues, whether it be sample size, proximity, or preciseness. Hopefully, when combined, the pieces of evidence will inform each other and give an overall picture that can be used to come up with the best available answer.

Without additional ado, here are the areas that I am planning on examining:

I. The Super Bowl teams and results, 1966-1969 seasons. The issue here is that we only have four games and eight teams. I will also compare these results to both prior NFL championship games and subsequent Super Bowls, to work backwards and find a reasonable range of outcomes, from cases where we do know the underlying regular season ratings.

II. The post-merger regular season results between former AFL and NFL teams, 1971-1975. We do have a good amount of regular season results, but the main problem here is proximity and relevance, since they take place after the period at issue.

III. Exhibition results between AFL and NFL teams. Beginning in 1967, the AFL and NFL teams played exhibition games. I know that exhibition results are not as reliable as regular season games, but I also don’t think these teams treated them quite as cavalierly as teams do today. I will examine the 1967-1969 exhibition results in aggregate as an additional piece of evidence.

IV. Expansion team comparisons. This idea comes from a comment provided by mrh in this post. He suggested looking at the Dallas Cowboys and Minnesota Vikings, two expansion teams that joined the NFL near the time the AFL began, to find out how long it took those teams to become competitive with existing NFL franchises. I’m going to expound on that idea, and do an in-depth look at other expansion teams, how they were assembled, and the factors, both positive and negative, that the AFL teams faced compared with in-league expansion teams.

V. Draft results. 1960 NFL draft; 1960-1966 AFL and NFL drafts; 1967-1969 combined drafts. I actually think this can be very powerful evidence of how the leagues compared, and whether the AFL was closing the gap over time by getting equivalent young talent. It is the one case where the two leagues went head to head over the decade with a large sample size. The problem here is determine the draft value each league obtained each year. If we take a post hoc look at the players, we run into some circular issues of interpreting the data. Is a first-team all-pro or a year started the same in the AFL as the NFL? On the other hand, rating the drafts based on draft position and number of players signed by each league has its own problems. Namely, the two leagues had separate drafts. Often times, players had vastly different draft positions, and I suspect this is as much to do with signability as differing scouting evaluations. Were the NFL and AFL so bad at scouting that they failed to draft Buck Buchanan and Tom Mack anywhere near the top 100 picks, when they were high picks in the other league’s draft? I doubt it. I am still debating on how to evaluate draft value given these issues, so any thoughts would be appreciated.

VI. Macro-level roster analysis for both leagues. Chase suggested that I look at rookie starter rates of the two leagues, to see when the AFL normalized with the NFL. I did that (you’ll have to wait for the results) and am going to expand that to also perform age analysis, analysis of the composition of all-pro teams in both leagues, and roster and starter turnover rates.

VII. Player movement between leagues, and Individual player performance trends. Here, I’m going to look at it on an individual and group level, primarily at the offensive positions where we have measurable statistics. To the extent there were players that played extensively in both leagues (and there probably aren’t many), I’m going to compare their performances relative to age in both leagues. Further, I’m also going to compare player performance within leagues. How did original starters in the AFL in 1960 do in 1964 when they should have been hitting their primes? What about those that entered in 1963, how did they do 3 years later? This information may give us a sense of the rate at which the AFL was improving in talent, and when it levelled.

My plan is to have several posts, culminating with a final one in July or August, hopefully tying it all together. How many posts will there be? I don’t know. It depends on where the research leads, how much information there is, and any additional ideas developed by you. My goal is to touch on one of the topics every couple of weeks or so. I’m going to start with the Super Bowl teams in the next post. After that, the order will probably depend on where the research and comments lead.

Often times, we post our research after we have developed the methodology and produced the results. But with this project, I think it is the kind of thing that many of our intelligent commenters will have good ideas to contribute, to make the final product better. I’ve put a fair amount of research in already, but I’m certainly looking for different ideas to test my thoughts. And hopefully, at the end, we will have a fair and detailed look at the AFL, NFL, and the state of the game in the 1960’s.