Covers.com is the biggest and best source for sports betting information, providing unrivaled and original content sports bettors cannot live without.

Betting on the NFL preseason isn’t the wisest thing to do but neither is eating red meat, drinking Coke or watching How I Met Your Mother on Netflix. A tiger can’t change his stripes and this degenerate can’t stop from betting on the NFL games in August.

So, if you’re like me and willing to dabble in the murkiness of exhibition pro football games, please, allow me to give you one tip: Pay attention to the coaches.

Yes, these games are meaningless but NFL coaches are among the most competitive people on the planet. They work 20 hours a day not because they love the job so much – it’s because they can’t sleep thinking another coach is working harder and getting an edge.

Some head coaches can’t cut turn off the thirst for Ws even in the preseason. A win is a win and if they’re keeping score, it’s always better to be on the team with more points.

Here’s a look at the three best head coaches against the spread in August over the last three years.

Mike Zimmer, Minnesota Vikings

11-2 ATS, 12-1 SU

The former Cincinnati Bengals defensive coordinator has been running the show in Minnesota since 2014. He lost his starting quarterback, Teddy Bridgewater, to injury in practice at the tail end of August, but that didn’t stop his team from going a perfect 4-0 ATS in the preseason.

Zimmer normally does the defensive play calling for the Vikings but he may let his defensive coordinator handle the responsibility in the preseason.

The Vikings are 3-0 SU and ATS in Week 1 of the preseason under Zimmer. The Vikes are 1-point road underdogs against the Buffalo Bills in their first preseason game.

John Harbaugh, Baltimore Ravens

10-2 ATS, 9-3 SU (Since 2014)

The Ravens have never done worse than 2-2 against the spread in the preseason since Harbaugh took the head coaching job in 2008. Baltimore is covering in nearly 64 percent of its exhibition contests since then.

Harbaugh, though, has been vocal about his distaste for the lengthy preseason slate and last year told reporters he’d get rid of preseason games altogether if it were up to him.

Ravens starting quarterback Joe Flacco is out temporarily with a sore back and Baltimore is scrambling to sort out its QB depth chart before the start of the season. The Ravens are considering signing free agent Colin Kaepernick and even brought in arena-league QB David Olson.

Baltimore is a 1-point home fave against the Washington Redskins next Thursday.

Jay Gruden, Washington Redskins

8-4 ATS, 9-3 ATS

The first three years of Jay Gruden’s coaching career haven’t gone as well as Redskins fans would have hoped. Gruden hasn’t jelled with any of his quarterbacks in Washington and the team is a middling 21-26-1 straight up in the Gruden era.

At least football fans in the D.C. area can take solace knowing their team covers the spread 66 percent of the time in August under the lesser Gruden brother.

Copyright © 2017 Score Media Ventures Inc. All rights reserved. Certain content reproduced under license.