Former NFL coach Bill Belichick has revealed what exactly went wrong for the Kansas City Chiefs and Andy Reid at the Super Bowl.

As far as Belichick is concerned, Chiefs coach Reid made one key mistake at Caesars Superdome in New Orleans which helped the Philadelphia Eagles stop the Chiefs from achieving a historic three-peat.

The former New England Patriots leader, who is a multiple Super Bowl winner, spoke to the Let's Go! Podcast about what went wrong for the major favorites.

"For Kansas City this year, a good place to look is the left tackle situation. Clearly, Andy and Brett (Veach) the general manager identified that as a problem and, you know, they took Kingsley (Suamataia) in the first or second round whatever it was," Belichick began.

"They took him high as the second pick after Worthy. That didn't work out and then they played four offensive tackles with their last offensive tackle at the end of the season in the playoffs being Joe Thuney who's really a guard. He's never played tackle since he played it at NC State in college."

According to Belichick, the solution that Reid and his staff found to their problem was not successful enough and ultimately proved costly.

"They knew what the problem was. They tried to address it. It didn't work out with Kingsley, it didn't work out with (Wanya) Morris. Then they made a trade that didn't work out and now they ended up playing a guard at tackle," he said.

"You get up against some teams and you can get by with that, but until you get up against the best teams or the best team, that was a problem for them. It was a problem for them in the Super Bowl."