ORCHARD PARK, N.Y. -- What's the difference between an 9-0 record and a 3-6 record?

Three.

That's how many turnovers the Buffalo Bills committed in Sunday's 23-13 loss to the Kansas City Chiefs, who did not turn the ball over once.

Despite out-gaining Kansas City more than 2-to-1 in offensive yards -- 470 to 210 -- the Bills couldn't overcome their critical mistakes to topple the undefeated Chiefs, who were trailing the Bills' 10-3 at halftime.

Understandably, that had Bills coach Doug Marrone fuming after the loss.

"I'm definitely frustrated. I am. Guys work hard all week, they bust their butts, the fans come, and they do a great job and we have a chance to get a good score and a lead in this game," Marrone said. "And we can't finish it."

For more than a half, the Bills looked like the better team. Undrafted rookie quarterback Jeff Tuel, making his first career start, lobbed a 59-yard touchdown to fellow rookie Marquise Goodwin late in the first quarter, helping to build a lead against a stagnant Chiefs offense.

But it was Tuel's third-quarter interception -- returned 100 yards for a touchdown -- and later, a T.J. Graham fumble -- returned 11 yards for a touchdown -- that made all the difference in this game.

"We knew coming in that this team scored a lot of points off turnovers," Marrone said. "They had 17 off of turnovers [on Sunday]. ... When it's time to make the plays, you have to make the plays and we didn't do that."

With replacement starter Thad Lewis "not close" to being ready to play, according to Marrone, the Bills turned to Tuel, who went 18-of-39 passing for 229 yards, one touchdown, and two interceptions.

"Did Jeff play well enough for us to win? At times," Marrone said. "At times he didn't. I think you could say that about a lot of people."

The Bills didn't reveal their decision to start Tuel until Sunday, after holding out hope that Lewis could play through sore ribs that kept him out of practice Wednesday and Thursday, while limiting him Friday.

"It's tough with the situation we had because you never really know what the coaches are going to say," Tuel said. "I kind of had a feeling that I was going to go, just as far as talking to Thad and seeing how he was doing physically."

Tuel is the third inexperienced quarterback that Marrone and offensive coordinator Nate Hackett have started this season, joining Lewis and first-round pick EJ Manuel.

"I think whenever you have a young guy ... we've had to do whatever we can to make them feel comfortable back there," Hackett said. "It's frustrating. It's hard. You want to develop a guy. ... We haven't had that option yet. I give Jeff a lot of credit. That was the first game he's had to play where he's had a practice coming into [it]."

Young quarterback or not, Marrone's frustration was evident.

"I have high expectations. It's my responsibility to put a guy out there that can win," Marrone said.

And Marrone thinks his team is close to winning.

"This one hurts. It hurts me, it hurts the guys in the room. I hurt for them. I hurt for our fans. It's a tough one," he said. "We're not out of the playoffs. We're a good football team that is not making the plays that we have to make. We play extremely hard, we fight through adversity, but we're just not making the plays at the times we need to make [them]. And that's everybody."