The story has been the same for the Vikings the past three weeks, just tweak the opponent a little bit and adjust the final score.

     The story has been the same for the Vikings the past three weeks, just tweak the opponent a little bit and adjust the final score.
     Minnesota builds impressive first-half leads, pounding the ball behind Adrian Peterson and looking every bit the part of a juggernaut. Then the Vikings head into the locker room and all the momentum slips away. Any lead goes right along with it.
     "You're disappointed when you don't finish games," Vikings coach Leslie Frazier said this week. "You're judged by wins and losses, and we need to get some wins."
     So do the Chiefs.
     Two of the five winless teams left in the NFL meet at Arrowhead Stadium on Sunday, both desperate for a victory. The Vikings have come close, while Kansas City is only beginning to show signs of life after one of the most dismal starts in league history.
     "I don't know about must-win, but it's one we need to win," Frazier said. "We need to win this game for a lot of reasons, and we have to go out and play well and do it four quarters.
     "It's very, very important for us to get a win."
     No pressure, huh?
     The Vikings squandered a 17-7 lead at San Diego in a 24-17 loss, and then watched a 17-0 lead over Tampa Bay turn into a 24-20 defeat. The ultimate disappointment occurred last week, when Minnesota led division-rival Detroit 20-0 at halftime. At home, no less.
     Matthew Stafford threw two touchdown passes in the second half, the Lions rallied to send the game to overtime, and Jason Hanson's field goal doomed the Vikings to another defeat.
     "I don't know if I've ever started out 0-3, but you go through things through the course of a year," quarterback Donovan McNabb said. "Then you find one or two particular games that turn your season around. Could this game be it? It possibly could be. But at this particular point, we need to focus on getting this win, doing whatever it takes to win."
     There are certainly reasons to believe it'll happen.
     Peterson is just shy of 300 yards rushing for the season, giving Minnesota its typically stout ground game. McNabb has shown signs of brilliance, sporadic as they may be. Defensive end Jared Allen is coming off a three-sack performance against Detroit, and is going for a sack in his sixth straight game, while Ryan Longwell has hit 14 consecutive field goals.
     Not to mention the Vikings are facing a Chiefs team in disarray.
     Besides losing their first three games, the defending AFC West champions have also lost safety Eric Berry, running back Jamaal Charles, linebacker Brandon Siler and tight end Tony Moeaki to season-ending injuries. Cornerback Brandon Flowers is nursing a bum ankle, and wide receiver Jon Baldwin — their first-round draft pick — is still out with a thumb injury.
     The Chiefs were blown out 41-7 by the Buffalo Bills in their opener and 48-3 by the Lions, but finally showed some moxie last Sunday at San Diego.
     After digging another 10-0 hole by halftime, Kansas City came out firing. Matt Cassel started to look downfield, wide receiver Dwayne Bowe finally got open, and the offense found some life after a miserable preseason that bled straight into the regular season.
     "You know, what I'm proud about is that collectively we've come together," Cassel said, "and we're working to get this figured out and go down the right path, and hopefully that will result in a win for us sooner than later."
     Both teams hope that's the case. There's a big difference between being four games under .500 and two games below the break-even mark.
     "It's very important for our guys to understand that you can't dig too deep of a hole," Chiefs coach Todd Haley said. "We've already lessened our margin for error."
     Like Frazier, Haley is optimistic that his team will figure things out. Even though it's little secret that Haley's job status is uncertain — he has one year left on his contract — he insists that his only concern is turning around what many view as a sinking ship.
     Perhaps the "Suck for Luck" movement embraced by some Kansas City fans demonstrates how far the Chief have fallen. After winning the division just last season, some fickle fans are so disgusted by their lousy start that they're openly rooting against them. That way, they'll have the No. 1 pick in the draft and could conceivably select Stanford's Andrew Luck.
     Well, one team is going to have a leg-up in that race after Sunday.
     It could be the Chiefs. Could also be the Vikings.
     "It could be the best game of the week," Minnesota defensive tackle Remy Ayodele said, almost philosophically. "Someone's got to win."