You have to go back to 2006 to find the last time the Colts won a road opener. The Colts have had problems playing in Jacksonville's humidity losing during their past three visits by an average margin of 14.6 points. 
Philip Rivers is learning a new system. He's played his entire 14-year career with the Chargers. Rivers clearly is well past his prime. He had a 12-year low in passer rating last year. The Colts brought in Rivers figuring he would be an upgrade on Jacoby Brisset. They both had the exact same low passer rating, though, last season. 
 Jacksonville's secondary is gutted, but its defensive front seven is respectable. Josh Allen is the best pass rusher on the field. 
The Jaguars have youthful talent on offense. These guys are hungry to make their mark. 
Maybe later in the season, the Jaguars might begin tanking. But not now. This is going to be very tough for the Colts to win their first Game 1 game in six years. Much tougher than the marketplace thinks.