Bear With Me

It's been a busy time for voting and elections generally, but it would be remiss of me to not discuss the big news this week.

That's right! It's Fat Bear Week!

Fat Bear Week is an annual voting contest run every year since 2014 (though in 2014 it was called Fat Bear Tuesday and lasted only one day). Votes are placed through an elimination bracket system to determine a winner, but the rules are vague as to what the voting is on.

Photos of the Bears of Katmai National Park are shown in before-and-after style of their pre-winter torpor weight gain, suggesting the votes should reflect the fattest bear, the most weight gain, the most proportional weight gain or something similar to this. Each of these could be more objectively measured than through public collective guesswork so I have to expect that people are really just voting for their favorite bears.

Whatever the intent is, the votes are already underway and wherever there's a poll there's an opportunity for a statistically dubious prediction based on publicly available (i.e. incomplete) data!

It seems the contest has been run over multiple platforms, originating on Facebook and currently held on the Explore.org webpage. This made past results a little difficult to track down, but I am running off the following as my data sources: 2014, 2015, 2016, 2017, 2018, 2019, 2020.

As a first port of call, it's worth considering the past winners to see if there are any patterns, and early on there are:

2014: Bear 480 ('Otis')

2015: Bear 409 ('Beadnose')

2016: Bear 480 ('Otis')

2017: Bear 480 ('Otis')

2018: Bear 409 ('Beadnose')

2019: Bear 435 ('Holly')

2020: Bear 747

Evidently there is a good level of consistency among winners with two bears taking out the first 5 wins. This is promising as it suggests there is merit in considering past form, but as the two most recent winners break this streak it is possible that both Otis and Beadnose are past their prime.

Holly, as it happens, was eliminated in the first round and Beadnose is not in the running in 2021. This leaves Otis and Bear 747 as favourites at this stage and, at time of writing, they are paired off against each other for the Round 2 vote. In a matter of hours one of these will emerge victorious and be the hot favourite heading into the finals. Otis is coming in on the back of a Round 1 victory against Bear 402 who debuted in the first competition in 2014, while Bear 747 is coming in fresh from a bye. And this leads to an interesting point about the history of byes in Fat Bear Week.

An interesting point about the history of byes in Fat Bear Week

Since its inception, Fat Bear Week has run four Round 1 match ups followed by the winner taking on a bye. There is no shortage of bears in Katmai to flesh out the contest to 16 contestants and remove the byes. The bye system does work well for a week-long contest but I have to believe that is a coincidence as the 2014 contest introduced this format despite lasting only one day.

My theory is that the bye system is for the drama, introducing new bears into the contest after the first couple of days are done. Interestingly, the byes do very well in later rounds. Two thirds of byes (19/28, 2021 results unclear) win their debut match up, and with the exception of 2018 every Fat Bear Week winner had a bye. (In 2018 Bear 409 'Beadnose' won, and although not a bye that year has been one twice before this).

There is also a very select pool of bye bears. Over eight years only ten bears have held a bye:

Bear 32 ('Chunk') - 2017, 2019, 2021

Bear 128 ('Grazer') - 2020

Bear 409 ('Beadnose') - 2014, 2015 (won)

Bear 410 ('Four-Ton') - 2014, 2015, 2016, 2017

Bear 435 ('Holly') - 2016, 2018, 2019 (won), 2020

Bear 480 ('Otis') - 2014 (won), 2015, 2016 (won), 2017 (won), 2018, 2020

Bear 503 ('Cubadult') - 2019, 2021

Bear 747 - 2014, 2015, 2016, 2017, 2018, 2019, 2020 (won), 2021

Bear 856 - 2018

Cub of Bear 132 - 2021

This may provide a hint as to the success of the bye bears. Perhaps, to maximise the drama of Days 3 and 4, public favourites are preferred to fill the byes.

This may give us some insight on who to watch in 2021. Yesterday Cub of Bear 132 won from a bye, but Bear 151 'Walker' beat the other bye, Bear 32 'Chunk'. Currently the remaining byes (Bears 503 and 747) are lagging behind their rivals, which would make this only the second time that less than half the byes progressed. The other case was in 2018, when former bye Bear 409 'Beadnose' ultimately won.

While we're looking at form...  

There are a good number of bears who have competed across multiple years, but due to the elimination bracket system that's no guarantee they've run against each other. The table below compares all multi-contest competitors (2014-2020) and identifies those that have met more than once.

If the results of past contests were perfectly predictive of later ones, we would see this in the golden examples above--Bears 32 and 747 have been run against each other five times and we would expect the same bear to win each time. If the past has no bearing, we would expect about 50% of the rematches to give a different result. This latter scenario is closer to the truth:

  Bear 32    5 matches with Bear 747    2 wins, 3 losses

  Bear 32    2 matches with Bear 856    2 wins

Bear 151    3 matches with Bear 480    1 win, 2 losses

Bear 151    2 matches with Bear 856    2 wins

Bear 402    2 matches with Bear 854    2 wins

Bear 409    2 matches with Bear 410    2 losses

Bear 409    3 matches with Bear 480    2 wins, 1 loss

Bear 410    3 matches with Bear 480    3 losses

Bear 435    2 matches with Bear 747    1 win, 1 loss

Bear 435    2 matches with Bear 854    1 win, 1 loss

Around half of the repeat matches have consistent results, and only one example (410 v 480) exists where three or more consistent results were recorded. Therefore while form seems useful in picking a winner it is not as reliable in resolving individual match ups.

Current state of play

At time of writing the brackets for 2021 are as follows.

Previous winners still in the running are Bear 480 ('Otis') and Bear 747. In a matter of hours one of these will be outpolled and the other will be the smart money for Fat Bear Champion 2021. This pair have only matched up once before, where they vied in the final for 2017 Champion, which Otis ultimately won. As just discussed, however, this isn't much of an indicator that Otis will win again.

Otis has the most wins of any bear (2014, 2016 and 2017), but 747 won in 2020, where Otis lost in the second round after a Round 1 bye. It is entirely possible that Otis's days at the top of the Fat Bear tree are behind him, having lost his first round every year since his last win--a streak he broke on September 30. This win was comprehensive (71,227 votes to 14,026), and there are no shortage of Otis fans on the web.

This makes the Otis-747 match up a tough one to call, but early results have Otis ahead at a rate of around 3:2.

Currently today's other race has 812 ahead of 503 by a ratio of 4:3. That will leave the semi-finals with Bear 151 ('Walker'), Cub of Bear 132, 480 ('Otis') and 812.

Semi Finals

Bear 151 ('Walker') has contested every Fat Bear Week since 2016, but with little success. He has never been a bye and only made it past round two once (2020). Walker is up against the newcomer 'Cub of Bear 132', who is too young to have either name or number yet.

Cub came in as a bye and may be a crowd pleaser with its youthful looks and baby fat, but only narrowly defeated Bear 128 ('Grazer') 40,968 votes to 32,251 (= 56.0%). Grazer was not a particularly strong contender based on previous Fat Bear Weeks or on a similarly close first round victory over 2019 winner Bear 435 ('Holly').

By comparison Walker made the semifinals last year and has had two decisive wins this year with 64,451 votes to 11,820 (= 84.5%) in Round 1 against Bear 634 ('Popeye') and 60,621 to 11,038 (= 84.6%) in Round 2 against three-time bye Bear 32 ('Chunk').

If this represents a strong support for Walker rather than a tough pool for Cub, it's hard to see how Walker doesn't make the finals.

Prediction: Walker beats Cub of Bear 132

Bear 812 is the expected winner of today's first poll. This bear suffered a first round loss in 2018 and second round loss to eventual champion Bear 747 in 2020. This year it pulled a decent win over Bear 131 (68,092 to 17,706 = 79.4%).

However, the expected winner of today's second poll is three-time Fat Bear Champion Otis who preformed even better in Round 1 against Bear 402 (71,227 to 14,026 = 83.7%). The form, performance and fame make this an easy win for Otis.

In the event Bear 747 beats Otis today, this is does not meaningfully improve 812's chances.

Prediction: Otis beats Bear 812

On their current polling numbers (83-85%) Walker and Otis may look well matched, but again Otis's history as a three times winner really sets him apart.

Prediction: Otis beats Walker, Wins Fat Bear Champion

This would make 2021 only the second time a non-bye bear has won, and like the first time it would be to a previous bye-holding winner. The second most likely outcome to my mind is an upset win by 747 today that puts him in Otis's place on the Fat Bear throne.