Take baseball. I am sure everyone has seen that commercial, don't even know what product, but it is talking about analytics and it says "Plus it is 90degrees out today and the ball will travel 6.6 feet further." (not sure if that is a real analytics number or something made up for the commercial). BUT the ball does travel further in hotter temps. Anyone that watches baseball knows this. Fly balls that are routine fly outs in April and September/October are homeruns 5 rows deep in July and August in the same park.

So remember the severe heat wave across almost the whole U.S. in late June? Check the baseball scores. For about a week to 10 days most game were going over the total. 11 or 12 of 15 games almost every day. And while that heat wave broke, overs continued to be extremely profitable for about 8 weeks until the end of August, when parts of the U.S experienced cooler temps (for August). Totals were adjusted as this 8 weeks went on, but they still were a bargain (excluding Colorado home games that were overpriced), especially if you looked at every game individually. Check the temperatures at each stadium, and stay away from teams that don't hit or rely on home runs and you did quite well.

Even games that looked to be a pitchers duel by the lines with an over/under of 6.5, would end up 7-4 or some over number. I was slightly above water (.500) with baseball for the year, but really it was all about those 8 weeks of hitting overs. By definition that was +EV. Those are the things and plays you have to find within the season. it may not make the whole season and every play combined +EV, but it can significantly reduce the 4.5 -EV

Half Smokes first two week play of the NFL season is another.