Since entering the NFL as the No. 1 pick in 2015, Jameis Winston hasn't won many regular season games (15) or playoff games (0). But he's won big in the offseason -- particularly, this year.

The Buccaneers didn't just sign DeSean Jackson -- the deadliest deep threat in the game since 2008. They also used their first-round pick on multidimensional tight end O.J. Howard. With Jackson and Howard joining Mike Evans and Cameron Brate, who established himself as a worthy pass-catching tight end in 2016, Winston's array of weapons looks like Daenerys' army of Dothraki, Unsullied, and of course, dragons.

The resemblance is uncanny:

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Make no mistake about it, the Buccaneers have joined the Patriots and Steelers in the NFL's upper echelon of offensive firepower.

Except at one position. The Patriots have the greatest quarterback of all time, Tom Brady, commandeering their attack. The Steelers have future Hall of Famer Ben Roethlisberger running theirs. The Buccaneers have Winston, who has yet to develop into the quarterback the team thought they were getting two years ago.

With good reason, the Buccaneers are already a trendy playoff choice heading into the 2017 season. In addition to their loaded offense, they boast an up-and-coming defense that includes Noah Spence, who appears to be on the verge of a mammoth breakout. The pieces are in place for a playoff run.

But the one player who will hold them back from reaching their playoff aspirations is Winston -- unless, of course, he finally cashes in on his potential, which made him the top pick over Marcus Mariota two years ago. That's because, to this point in his career, Winston has yet to play like a top signal caller. Winston is the Buccaneers' fatal flaw, the exhaust port built into the Death Star. He can be exploited.

That doesn't mean that Winston never will develop into an elite player. He enters his third season in 2017 and, as we all know, mastering the quarterback position is like mastering The Force. It doesn't happen overnight. It takes practice, patience, and persistence. Maybe 2017 is the year Winston awakens. In Andrew Luck's third season, he broke out for 40 touchdowns.

With that in mind, this isn't intended to be a hit piece on Winston. Again, no one -- not even Winston himself -- knows if he'll eventually transform into a top quarterback. This doesn't mean Winston is forever destined to be a middling player.

Instead, this is intended to look at why Winston is the Buccaneers' biggest question mark heading into the 2017 season, for which there are legitimate reasons for playoff hype. Based on the evidence he's given us in his 32 career games, Winston enters the season as the most likely player to hold back the Buccaneers' offense from making the jump to light speed.

The Bucs need their quarterback to turn into the player he was supposed to be. USATSI

Accuracy

Winston's main issue is his ability to throw the football to a spot that makes it easy for his receivers to catch it, which is an obviously important trait for NFL quarterbacks.

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Using the most basic (and somewhat flawed) level of analysis, Winston's career accuracy percentage of 59.6 ranks 33rd out of 43 qualified passers (minimum 200 attempts) since his rookie year. The 10 quarterbacks ranked below him are named:

More advanced statistics don't paint a prettier picture. Pro Football Focus tracks a statistic called adjusted completion percentage, which dismisses dropped passes, passes thrown away, spike balls, batted passes, and passes thrown as the quarterback was hit. Obviously, quarterbacks benefit from this metric as their adjusted completion percentage looks a lot better than their true completion percentage.

Winston's numbers were still bad. In 2015, Winston's adjusted completion percentage was a league-low 69.2. In 2016, Winston posted an adjusted completion percentage of 69.1, which ranked 26th of 29 qualified passers.

At least he's consistently inconsistent.

Turnovers

Given Winston's accuracy issues, it won't come as surprise to learn that he also experiences problems hanging onto the ball. He turns the ball over -- a lot. Part of that is due to his accuracy. But he's also a bad decision-maker.

Sometimes, both bad traits are on display.

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He's thrown 33 interceptions in his career to this point. Only two quarterbacks, Blake Bortles and Philip Rivers, have thrown more since 2015. He's posted a 2.99 percent interception rate in his career, which ranks 38th among 43 qualified passers in that span (again, 200 pass attempts is the minimum). Then there are the fumbles. Winston's already fumbled 16 times in 32 games -- tied for the eighth-most fumbles for a quarterback since 2015.

At one point last year his coach, Dirk Koetter, even publicly admitted to being concerned about his quarterback:

"Very," Koetter said, via the Tampa Bay Times. "I'm very concerned." If there's a bright spot, Koetter sounds like he thinks things could be worse. "He's not regressing, but we've got to take care of the football," the coach continued. "I mean, we've got to take care of the football. We can't turn it over three times in a half. We just can't do that.''

Winston's frequent turnovers even led to the Buccaneers noticeably scaling back their offense in a prime-time game. If Koetter doesn't trust Winston -- rather, if Winston can't execute an offense to its maximum capacity -- then the Buccaneers' ceiling is limited.

The deep ball

When Jackson chose to come to Tampa Bay (for the money, not the weather), fans and pundits lit up because they imagined Jackson hauling in bombs from Winston. While it's certainly true that Winston features a big arm and Jackson features Jason Bourne-like speed, it's also true that Winston's big arm hasn't always translated to the deep ball.

Jackson gives Winston one of the best home-run threats in football. USATSI

He wasn't a good deep passer in 2016, posting a 34.8 accuracy percentage on passes thrown at least 20 yards downfield, which ranked 20th out of 27 qualified quarterbacks, according to PFF. His passer rating on such passes was 71.0 -- 21st of 27 qualified passers.

He managed better numbers on deep balls in his rookie season, ranking 11th in accuracy percentage (42.2) and ninth in passer rating (99.1). So, maybe it's not fair to call him a bad deep-ball passer. But it is fair to say he's been inconsistent when throwing downfield.

Which is strange, because he's been throwing to Evans his entire career. But this is where his accuracy comes into play. Evans has posted ridiculous stats in his career, but they'd be dramatically improved if Winston could hit him more consistently down the field.

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The good news is that if anyone can help Winston out in that department, it's Jackson, who caught 50 percent of his deep (again, 20-plus yards downfield) passes last year, according to PFF. Since entering the league, no one has averaged more yards per catch than Jackson (minimum 100 catches).

The bad news is that if Winston struggles again on deep passes, he'll have no more excuses. When you're throwing to Evans and Jackson, your excuses are rendered useless.

Playoff dreams live or die with Winston

Again, just to reiterate, I'm not trying to condemn Winston as a quarterback who will always be bad. That's not fair to him. He's still in the early portion of his career, and it's not unreasonable to think he can improve as he ages. I'm not counting him out, because when he's at his peak, he's one of the best throwers in the league.

It's inconsistency that has dogged him. In nine career games, Winston's posted a passer rating above 100. In 11 career games, he's posted a passer rating below 80. Too often, he's either brilliant or terrible.

The Buccaneers have plenty of reasons to enter the season with hype at an all-time high. A year ago, their defense ranked 12th in DVOA. They signed the best free agent receiver and drafted the best rookie tight end. But they're only going to live up to their lofty aspirations if Winston begins to show signs of improvement as soon as this season.

Maybe it'll happen. Maybe Winston will be the league's most improved player. Maybe he'll make marginal upgrades. But one thing is certain: if he doesn't, he'll be the primary reason the Buccaneers falter.

How often does the team with the worst quarterback in the division capture the crown? That might be a bit unfair to Winston given that he resides in the same division as 2015 MVP Cam Newton, reigning MVP Matt Ryan, and Drew Brees (side note: How in the heck has Brees not won a regular-season MVP award?), but the point stands.

At some point, Winston needs to show signs of improvement. That point needs to be this year if the Buccaneers have any hope of playing football into January. Fair or not, the Buccaneers' success in 2017 comes down to Winston's progression as an NFL quarterback.