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The move from college football to the NFL is a forbiddingly deep one for any quarterback. No matter how "pro-style" your collegiate system may be, what you'll face is something you can never truly be prepared for until you've faced it and had it break you down. The players you'll face are better, the coverages are more complex and the blitzes more exotic.

The preseason helps, but you're likely coming in for second-half duty against second- and third-team defenders running schemes that take up a fraction of a normal NFL playbook. Quarterbacks who succeed in these environments must be viewed cautiously. You have to look beyond the occasional big play to see the repeatable positive trends to build on and reinforce the eradication of the bad habits that delay success.

Cleveland Browns rookie DeShone Kizer finds himself in those crosshairs. Kizer, who entered the 2017 NFL draft after two seasons at Notre Dame in which he completed 60.7 percent of his passes for 5,805 yards, 47 touchdowns and 19 interceptions, while adding 997 rushing yards and 18 rushing touchdowns.

Coming out to the NFL party as a redshirt sophomore, Kizer was bound to raise questions about his readiness—a process complicated by college tape that showed a slow internal clock to make throws and a questionable relationship with the structure of his own passing game. Kizer looked the part at Notre Dame, but he didn't always play the part. His inaccuracy during his combine workout didn't help, either.

Notre Dame head coach Brian Kelly added to those doubts when he laid it out more specifically.

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"He should still be in college," Kelly told SiriusXM NFL Radio of Kizer in April (via ESPN.com). "He needs more time to grow in so many areas, not just on the field but off the field … He's got a strong arm. Physically he's gifted," Kelly said. "He's got all those tools that you're looking for at the quarterback position."

As much as I blanch at Kelly's "off the field" comments for what they may imply about Kizer's maturity—there is no known blight on Kizer as a person—he does have a point about the quarterback's on-field acumen, driven by self-interest as it may have been.

Kizer, for his part, isn't short on self-confidence, putting forth the proposition in April to USA Today's Tom Pelissero that he has "the ability to be the greatest quarterback ever to play," and comparing his evolutionary self to a Frankenstein quarterback with Tom Brady's intellect and Cam Newton's body.

Of course, before he can go there, Kizer has to deal with the NFL bit by bit. The first step was his first preseason game, in which he completed 11 of 18 passes for 184 yards and the game-winning touchdown in Cleveland's 20-14 victory over the New Orleans Saints. At times, Kizer showed a real knack for the big play, completing passes of 52 and 45 yards. At other times, especially at the start of his turn in the second half, Kizer looked very much like a guy who was selected in the second round despite his obvious attributes.

"I think it was a great experience for him," Cleveland head coach Hue Jackson said after the game, per Patrick Maks of the Browns' official site. "There's a lot for him to learn from, but there was a lot of good things that he did, and he stood in there and made some plays with his arm. He will be the first to tell you there are so many things that he has to grow from. Just calling the play right, he will be the first to tell you that so he will grow that way, but there were some positives there, too."

"I'm sure he's in the locker room excited, but he'll be the first to tell you, there are so many other things to clean up."

Jackson's right to be cautious about Kizer's development. While the rookie did show a lot of potential on deep balls, the meat and potatoes of any quarterback's success—the consistent short and intermediate throws that sustain drives and define offenses—need work. And it's clear when you watch the reel of every Kizer throw that he's not quite there yet.

Jackson was also wise to start Kizer out with a series of plays in which he was primarily targeting receivers on swing passes and other first-read, easy-release routes. This allowed Kizer to get into a rhythm, and the addition of boot-action allowed him to get on the move and clear any potentially congested pockets. That said, he was still inaccurate on the easy stuff at first, but we can chalk that up to rookie jitters to a point.

With all those qualifiers in place, let's look at four plays from the fourth quarter that show both the good and bad of Kizer's NFL debut.

This 52-yard pass to receiver Richard Mullaney (No. 83) with 13:57 left in the game shows a lot of what makes Kizer potentially great. He's got to move out of the pocket to his left after Saints defensive end Al-Quadin Muhammad (No. 97) beats Browns tackle Roderick Johnson (No. 78) with an inside spin move.

Kizer's movement outside the pocket clears the rush and gives him an open window to play-fake and heave the ball downfield. The ball was underthrown, and defensive back Erik Harris (No. 30) should have had a bead on it for an interception, but when a young mobile quarterback re-sets his throwing base out of pressure and doesn't just tuck and run, that's something to build on.

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Here's another example of Kizer's out-of-pocket movement, though with less positive results. Here, he has to bail to his right after defensive end Obum Gwacham (No. 58) beats right tackle Matt McCants (No. 71) with an inside counter. As Kizer rolls to his right, he has both tight end Seth DeValve (No. 87) and running back Brandon Wilds (No. 31) moving the same way to give him openings.

Kizer actually has DeValve in the curl/flat area wide open quickly after the snap for an easy completion in a 1st-and-10 situation, but he chooses to extend the play without a clear target, and he has to throw the ball away. This kind of improvisation without a plan in place doesn't generally work out well at the NFL level.

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Kizer was also sacked three times for 22 lost yards, in the process showing how a sack isn't always the offensive line's fault. Sometimes, the quarterback takes too long to make a decision, and the breakdown is on him.

On this play, on 1st-and-10 and down 14-13 with four minutes left in the game, Kizer has a chance for an easy completion set up by scheme, and he doesn't take it. Running back Darius Jackson (No. 33) runs a quick outside route to the left from the backfield, and receiver Mario Alford (No. 15) helps further with a comeback route in which he gets in front of the defenders.

Kizer—who is looking to his left the whole time—doesn't pull the trigger on the throw, and both end Mitchell Loewen (No. 70) and end Muhammad (No. 97) take him down. That's on Kizer, because the game plan was set up for him to succeed. If you're looking for one play to amplify the concerns that Kizer doesn't yet play with a quick enough internal clock for the NFL, this might be it.

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Finally, the game-winning touchdown pass with 1:58 left. It's not a terribly complicated play—basically receiver Jordan Payton (No. 84) runs a go route past cornerback Damian Swann (No. 27) in man coverage. What stands out here is that Kizer takes a bad snap, re-sets and doesn't let the chaos around him get to him. It takes all he's got to get the ball to Payton for the 45-yard score, but he does show calm in the pocket on the play. If there's an upside to Kizer's slow internal clock, it's that he doesn't seem rushed when things go wrong.

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Unquestionably, you'll see Kizer as much as Jackson can play him through the preseason so that he'll have more reps against NFL competition and can build on that. Were I Jackson, I would not consider starting Kizer in at least the first half of his rookie regular season, if at all—he's on the line between potential and development that can ruin a young quarterback if he's thrown to the wolves too early.

Jackson has Brock Osweiler and Cody Kessler in his quarterback stable, and while neither option is particularly exciting (Osweiler is downright scary, to be honest), it's best for the coach to let his most talented quarterback prospect take his time to learn the NFL version of this game the right way.

Over time, the payoff could be great.

Doug Farrar covers the NFL for Bleacher Report. Follow him on Twitter: @BR_DougFarrar.