OAKLAND -- 

1.Two forgettable stretches prevented Browns from winning yet another nail-biter

The first quarter of the 2018 season is over, and the Browns haven't played a single meaningless snap. All four of Cleveland's games have come down to the wire, close enough for many inside the locker room to believe they should be 4-0 heading into next week's showdown with the Ravens.

Instead, the Browns are 1-2-1 after a gut-wrenching, exhausting 45-42 overtime loss to the Raiders.

"Close, but no cigar," offensive lineman Joel Bitonio said. "We had an opportunity to be 3-1 here, you know, 4-0. We were in every game, and there's little things every week. This week it was turnovers probably for us, we had kicks one week. Just things like that. We have to get over that edge though, we have to learn how to win as a team. We got one win, but we have to stack a few wins here."

In Sunday's back-and-forth shootout, two plays took momentum away from the Browns in moments when it appeared victory was in their grasp. What followed goes a long way toward explaining why Cleveland is lamenting its toughest loss yet in this roller coaster ride of a season.

"That's what gets you beat at this level, the games are so close and everyone's so talented," quarterback Baker Mayfield said. "You have to do everything right, you have to piece it together."

Leading 28-14 after punching the Raiders with a quick 10 points out of halftime, Cleveland had the ball with a chance to really put some breathing room between itself and the Raiders. The momentum vanished in a hurry when Mayfield was strip-sacked. Oakland fell on the fumble at the 7-yard line and promptly scored on its ensuing possession.

The Raiders followed with 13 more unanswered points during a stretch that included another Mayfield fumble and some stagnant offense to take a six-point lead early in the fourth quarter.

"They scored each time we turned it over and you look at the spread and that's the difference," Browns coach Hue Jackson said. "Can't turn the ball over. That's kind of uncharacteristic of what we've done on offense."

The Browns bounced back, of course, and found themselves in position to be one first down away from the victory formation. On third-and-2 with less than 2 minutes to play and the Raiders running out of timeouts, Carlos Hyde appeared to have enough for a first down. The ball was initially measured to be ahead of the first-down marker but a video review pushed it backward.

Much like they did the previous week, the Browns punted it away, giving the ball back to an opposing offense that didn't have any timeouts. It just didn't end the same way, as veteran Derek Carr drove the offense down the field in less than a minute and got the touchdown and two-point conversion Oakland needed.

With 14 seconds remaining in regulation and a little less than 20 yards out of Greg Joseph's field-goal range, the Browns never gave their kicker a chance. Mayfield was intercepted for the second time on the day, this one coming on a deep ball intended for Antonio Callaway.

The Browns went three-and-out on their only offensive possession in overtime. A second chance was all Oakland's offense needed in the extra period, and the game was over.

"They scored, but we gave them the opportunity to do so," Mayfield said. "We turned the ball over way too many times, gave them a chance in this league, when you turn the ball over like we did, like I did, you're not going to win those games. So we saw the end result of that."

2. Turnovers an issue, but Browns won't 'rein in' Baker Mayfield

The Browns committed to Mayfield as their quarterback earlier in the week and are ready to ride the waves that come with putting a rookie under center in the NFL.

Sunday's game had it all, as Mayfield made a number of No. 1-pick quality throws – his two touchdown passes certainly qualified – but was responsible for four turnovers – two interceptions and two fumbles. Jackson gave Mayfield a pass on his first interception, which was returned for a touchdown, but put the others on the rookie to process and absorb as mistakes that can't continue.

Jackson just doesn't want Mayfield to change a thing about how he attacks the game. It's why the Browns tabbed him the starter after his breakout performance the previous week against the Jets.

"Obviously he's going to learn," Jackson said. "I think football intelligence, as he goes through it, he'll understand and we've talked about it a little but just how important those things are. You got to be team protecting as you were saying in certain situations. But I don't want to rein him in because I like the things he's doing."

The confidence in Mayfield was evident early, as the Browns went for it on fourth-and-6 – Mayfield got the first down with a 6-yard scramble – and attempted two-point conversions after their first three touchdowns. The Browns converted two of three.

Mayfield finished his first NFL start 21-of-41 for 295 yards – fifth-most in NFL history for a quarterback making his first career start -- two touchdowns and two interceptions.

"He was always confident in the huddle no matter what happened, whether there was a turnover or a bad play, he was ready to play the next play," Bitonio said. "He showed some promise, I know he wanted to win, but we're getting there."

3. Browns will miss Terrance Mitchell, however long it is

The Browns lost one of their most pleasant surprises Sunday, and he could be gone for the rest of the 2018 season.

Cornerback Terrance Mitchell forced his way into the starting lineup by making play after play during training camp and he showed no signs of letting up through three games. Mitchell forced two fumbles against the Saints, caught the game-sealing interception against the Jets and teamed with rookie Denzel Ward to provide the kind of coverage the Browns have been missing for years.

Without Mitchell, who went down in Sunday's first half, the Browns used E.J. Gaines for the first extended time all season. Gaines, who hauled in a second-half interception, missed most of the preseason and was inactive Week 1 because of a knee injury.

The Browns will have this week of practice to toy with their options in the secondary before taking on the Ravens.

"Losing Money Mitch was big," Jackson said. "I had to move some guys around. I had to ask some guys to do some things they hadn't done in a while but that's pro football. You know that's the way it works. Next man up. The next guy has to step up and make some plays."