Fundamental lesson for Patriots: Week 1 loss doesn't define season

'Not good enough' is the phrase from Belichick (0:49)

Patriots head coach Bill Belichick is highly critical following his team's 42-27 home loss to the Chiefs. (0:49)

FOXBOROUGH, Mass. -- If New England Patriots coach Bill Belichick views the month of September as an extension of the preseason, as some former players-turned-analysts have said, Thursday's season-opening 42-27 loss was eye-opening in that regard.

The Patriots certainly looked like they were still in the preseason, while the big-play Kansas City Chiefs were regular-season ready.

What does it all mean going forward?

If history is any indication, beware of making any definitive declarations. The Patriots have lost a season opener and gone on to win the Super Bowl three times with Belichick and Brady.

They were thumped in Miami in 2014 -- the first regular-season game of Darrelle Revis' Patriots tenure -- and went on capture Super Bowl XLIX. Then there was the 2003 opener in Buffalo, a 31-0 loss that ultimately was the starting point in a 14-2 season that culminated in a Super Bowl XXXVIII triumph. Two years prior to that, it was a 23-17 loss at Cincinnati in the opener before the club went on to win Super Bowl XXXVI.

That doesn't mean the same thing will happen in 2017, but it's a reminder things are seldom as bad as they seem after Week 1.

And in turn, after an offseason in which media from coast to coast pumped the Patriots tires by wondering if a 19-0 season could be a realistic possibility, things are seldom as good as they seem.

So the key for any team at this time on the calendar is to avoid digging themselves a hole that will be too big to climb out of by midseason. And after a disappointing performance like the Patriots put forth, it's to get back to fundamentals.

"They weren't good enough," Belichick said of football's most basic things, such as blocking and tackling. The game also provided the Patriots a clear vision of what they need to work on to improve, which Belichick said is "a pretty lengthy list."

Start by eliminating the big play on defense, and picking up a yard on fourth-and-1, and the Patriots will be on their way.

Players are scheduled to be back at the stadium Friday to review the game. It won't be pretty, but by no means does that foreshadow how the rest of the season will unfold.

History decisively tells us otherwise.