Kansas City, Mo. ? If New England beats Buffalo Saturday, then Kansas City’s regular-season finale Sunday against Chicago will be as meaningless as an exhibition game.

But if the Bills beat the Patriots, the Chicago game becomes the most critical of the year for a Chiefs team that has been getting embarrassed on the road.

A New England victory Saturday ensures home-field playoff advantage for the Patriots and locks Kansas City into the No. 2 seed regardless of whether the Chiefs (12-3) win or lose against the Bears. But a New England loss means the road-challenged Chiefs could clinch home-field advantage throughout the playoffs by beating the Bears.

Getting to play every playoff game at home could be the difference between participating in the Super Bowl or watching it on television. At home, the Chiefs are unbeaten in 12 straight games. Their offense and special teams — and especially their defense — all have been considerably stronger at Arrowhead Stadium.

“I know for one reason or another we’ve been a totally different defensive team on this field,” coach Dick Vermeil said. “In that 12-game winning streak we’ve given up 103 yards a game rushing.”

Overall this year, the Chiefs rank dead last in rush defense, giving up more than 150 yards a game.

“I don’t know what’s different. Maybe we’re putting the wrong guys on the plane,” Vermeil said. “Maybe we’re putting the wrong coaches on the plane we fly with. But for some reason, it (does) make a difference.”

If the Patriots do win Saturday, Vermeil might pull his best players off the field early and not take a chance on any unnecessary injuries. That’s what he did when the St. Louis Rams faced the same situation in a 38-31 loss to Philadelphia in the regular-season finale of their 1999 Super Bowl season.

But in one respect, this situation is quite different. The Chiefs, reeling from a 45-20 blowout at Minnesota, might profit from an opportunity to regain confidence and momentum.

“I haven’t thought about it,” Vermeil said. “Right now, we’re just trying to prepare to win and keep a 13-game winning streak, maybe play well enough to gain a little bit of momentum and confidence back in our defense.