No serious hot dog totals handicapper would ignore the impact of weather before placing their bet. The common idea is that hot weather is tough on the eaters and bad for totals. But I always have had the opposite view, that hot weather and the associated impact on the hot dogs and water seems likely to relax the stomach muscles which would allow for more storage.
To drill down on the impact of temperature we will focus on the post-Kobayashi era since 2010, and use the average total HDB eaten for eaters ranked 1-5 in each contest (including the women's eaters where applicable). We use temperature readings from Newark airport which tend to be about three degrees lower than Coney Island but should be accurate for comparison purposes as the stations are only a few miles away. We arrive at the following data set:
Year Dog_Avg Temp Pressure
1 2010 41.20000 99 29.9
2 2011 47.80000 89 29.8
3 2012 51.20833 96 29.8
4 2013 49.55000 87 30.2
5 2014 43.83333 67 29.9
6 2015 45.70000 77 29.9
7 2016 48.30000 81 30.0
8 2017 53.10000 84 30.1
9 2018 52.40000 86 30.3
If we simply run a regression of top-five average dogs eaten versus temperature at this stage we find no correlation. However, my view is that the quality of eater has improved over this time period as eaters have found new training techniques and new competitors got into the sport following the Kobayashi-Chestnut boom. This should be included in the model. If we include a two-variable model with one variable being "years since 2010" and the other temperature, we get the following result:
The regression suggests an additional 1.25 HDB consumed per year and 0.23 extra HDB consumed per degree of temperature. Taking the average of top-five eaters ex-Chestnut and running the same process leads to a similar regression result.
With a forecast of 80 degrees tomorrow we'd expect roughly a wash between this year and the last, combining the influence of +1.25 HDB from natural eating performance gains and -1.35 from this year's contest being six degrees cooler than last year's. That would suggest a repeat performance in the 74 range. However, I personally like the under as I think we are reaching the limits of what humans can consume at the upper end similar to how gains have leveled off in similar events like the 100m dash. In addition, I don't think Chestnut's form looks good from recent events and he is moving into his mid 30s. Chestnut is no doubt the LeBron or Jordan of eating but even those greats slowed down at some stage and competitive eating seems every bit as physical as basketball if not more so.
One last note, I think that under 74.5 laying vig seems bad compared to under 73.5 +120 or so, which a lot of shops are dealing, because if he falls on the number of 74 they will probably do some bogus "recount" and give him the record, plus he might be motivated by the record at the very end. For these reasons I don't think 74 is a very live number and you are better off taking under 73.5 or finding over 74.5 if you like the over.