Lead Article of Volume in ‘Journal of Sports Economics’

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There was a nice surprise yesterday, when I discovered that my latest published article – in the Journal of Sports Economics – has been assigned as the lead article of this year’s volume (16). Signals seem to be mixed on whether this actually means anything in terms of esteem or quality judgements, but a well-known empirical regularity is that lead articles do tend to get more citations other things being equal (see, for example, Coupé, Ginsburgh and Noury, 2010, in Oxford Economic Papers), so here’s hoping.

The article itself adjusts win percentages of NFL teams to account for strength of schedule, prior to calculating standard measures of competitive balance. I find that the adjustment makes the NFL (already considered the epitome of competitive balance) look even more balanced. For the record, the details are as follows:

Lenten, L. J. A. (2015), “Measurement of Competitive Balance in Conference and Divisional Tournament Design”, Journal of Sports Economics, 16(1), 3-25.

You can view the abstract here, and e-mail me if you would like a copy.

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NFL Scheduling and Competitive Balance

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[Archived from: The Sports Economist, 2 January 2014]

In this paper (now forthcoming, JSE: doi: 10.1177/1527002512471538), it was shown that for every single year after the expansion to 32 teams in 2002 (until 2011), the NFL was even more competitively balanced when the strength of schedule was accounted for, without exception, using four common CB measures. Previous The Sports Economist posts on this are here and here.

Since the 2013 regular season has just been completed, we crunched the numbers on the two most recent seasons. The streak remains unbroken, once again demonstrating the importance of adjusting CB measures for unbalanced schedules.

2012:

Standard Deviation Ratio: 1.5245 (unadjusted); 1.4645 (adjusted)

Herfindahl Index of CB:  1.1453 (unadjusted); 1.1340 (adjusted)

Concentration (12) Ratio:  1.4010 (unadjusted); 1.3889 (adjusted)

Gini Coefficient:  0.2776 (unadjusted); 0.2647 (adjusted)

‘ABC News Breakfast’ Newspaper Segment

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Another ABC News Breakfast newspaper segment (filmed Monday last week, 6 February) discussing the typical range of stories in the news that day, with Michael Rowland and Karina Carvalho.

WATCH ON YouTube

Liam Lenten – on ABC1 News Breakfast again, sharing thoughts on mining barons in the media, Gillard leadership speculation, Super Bowl advertising and Thierry Henry back on the EPL scorers’ list.

The First Two Data Points Say “…mmm, I’m Not Sure Yet”

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[Archived from: The Sports Economist, 23 January 2012]

The new NFL overtime rule, see page 111 (introduced last season for playoff games only) finally became binding in the current playoff series two weeks ago, and then for a second time yesterday. Of most interest to economists about the rule change is its potential for teams to alter their overtime strategies in response to the element of the rule that both teams are now guaranteed a direct opportunity to score.

While it’s far too early to make firm inferences about this, it’s worth recounting that the primary intention of the rule was for the result of the coin toss determining which team gets to receive the kick-off (and consequently first possession) to have less power in determining the match winner (previously almost 60% of the nearly 500 overtime games since 1974). At the margin, we might also expect touchdowns to be the winning method of scoring slightly more often than previously, since it is now the only way that the team with first possession can effectively kill the game without the opposition getting the chance to equalize.

On the basis of these first two observations, it is interesting to note that the qualitative outcomes were very different – while winning the toss allowed Denver and Tim Tebow to end the contest on the first play via a touchdown, both NY Giants and San Fransisco each failed to score on their first possession, triggering reversion to sudden death as previously, which was won eventually by the former. [Disclaimer: I have only recently followed the sport, so feel free to critique this via comments.]

While this (admittedly premature) anecdotal evidence suggests that the coin toss is more influential than before, the reality is about as mixed as could have been expected. Someday – perhaps in a few decades or even within the decade should the rule be extended to the regular season, one of our esteemed TSE colleagues will no doubt crunch the numbers on this rule change when there is a sufficient (presuming due restraint exercised) sample size.

NFL Even MORE Competitively Balanced (Yet Again)

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[Archived from: The Sports Economist, 3 January 2012]

Further to an earlier post one year ago to the day, the same result occurred upon conclusion of the 2011 NFL season as in EVERY previous season since the re-alignment to 32 teams in 2002 – that the  NFL is even more competitively balanced when the standings are adjusted for strength of schedule (than on the basis of raw standings) .

Even though this season was noticeably less balanced than (the recent) average without adjustment, the difference from the adjustment was even more pronounced than any other season during this period (with the exception of 2003), making adjusted competitive balance about average over the same period.

On this occasion, the actual-to-idealized standard deviation ratios are 1.611 (unadjusted) and 1.462 (adjusted); the Gini coefficients are 0.292 (unadjusted) and 0.260 (adjusted); and the Herfindahl indexes of CB are 1.162 (unadjusted) and 1.134 (adjusted).

Ultimately, this result reinforces further the need to account for strength of schedule in producing standard competitive balance metrics for various empirical studies!

NFL Even MORE Competitively Balanced than We Thought

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[Archived from: The Sports Economist, 3 January 2011]

With the NFL regular season having reached its (customarily gripping) climax moments ago, sports economists will take note, as usual, of the within-season competitive balance measures, based on the end-of-season standings.  The figures generated from these measures are often used in the literature on the effectiveness (or otherwise) of labor market and revenue-sharing policies used by leagues to maintain/improve competitive balance.

On the basis of these measures, it is generally accepted by sports economists that the NFL has been the most competitively balanced (on average) of the four major leagues over the last few decades.  However, there is continued debate as to the degree, if any, to which this outcome has been generated by various NFL policies that are not used by the other major leagues – for example, the comprehensive revenue-sharing arrangement from the centralized national broadcast contract.

The 2010 season was, according to the popular actual-to-idealized standard deviation ratio, the second-most balanced NFL season since 2002, and it is the same story if one instead uses other popular measures, such as Gini coefficients or Herfindahl indexes.  This result is favorable to those that believe in the invariance principle – that arguably, this is some (albeit very limited) evidence that the salary cap was not previously contributing much towards making the NFL so balanced.

Another policy that is often ignored in this analysis is fixture design.  One thing that distinguishes the NFL from the other major leagues is that the fixture has a strength-balancing element to it.  Specifically, as explained in the Wikipedia NFL page:

Each team plays once against the other teams in its conference that finished in the same place in their own divisions as themselves the previous season, not counting the division they were already scheduled to play.

With this in mind, one might be tempted to wonder to what extent the higher level of balancedness in the NFL is attributable to this scheduling policy.  After all, if below-average teams are playing other below-average teams more often (think: NFC West), mutatis mutandis for above-average teams, then the standings could arguably provide a distortive impression of balancedness.

In an attempt to answer this question, I extended a model from a paper just published in Economic Modelling (on the Australian Football League) to adjust the win percentages of the 32 teams, according to the strength of the schedule that each faces, prior to calculating the within-season measures.  The upshot is that the power-balancing aspect of the fixture does very little to create an illusion of greater balancedness, and that this is overwhelmed easily by other biases in the fixture, specifically the design requirement to play teams in one’s own division more often than teams in other divisions (especially so for divisions in the other conference).

Ultimately, on the basis of the adjusted win percentages, the NFL is found to be even more competitively balanced than on the basis of the original win percentages in every single season over the 2002-2009 sample, according to each of the four measures used.  Furthermore, the average difference is statistically significant.  A draft of the paper can be found here (any comments welcome).  For the record, 2010 produces the same outcome yet again (note that higher means less balancedness): the actual-to-idealized standard deviation ratios are 1.474 (unadjusted) and 1.362 (adjusted); the Gini coefficients are 0.264 (unadjusted) and 0.203 (adjusted); and the Herfindahl indexes of CB are 1.136 (unadjusted) and 1.116 (adjusted).  Furthermore, while the adjustments almost always dictate some differences in playoff outcomes, 2010 was highly unusual in the sense that the adjusted standings would have produced the identical 1-6 playoff seedings in both conferences.

Some economists argue that the NFL is, if anything, too balanced.  Therefore, you can interpret this result as you like.  Nevertheless, having repeated the exercise using NBA data and finding that this ‘unbalanced schedule’ adjustment makes no difference, we can conclude that for comparative purposes, accounting for differences in strength of schedules is an important element of using empirical major league evidence on competitive balance policies.  This is especially the case if one wishes to compare the major leagues with the major soccer leagues of Europe, in which each team plays all other teams the same number of times.