Jameis Winston and Marcus Mariota are defying history.Often, for every star quarterback taken atop the draft, there has been a flop. A Bledsoe and a Mirer. A Manning and a Leaf. A McNabb and a Couch. A Luck and a Griffin.After two seasons, Winston and Mariota are poised to become the franchise quarterbacks the Bucs and Titans hoped they would be. In 2015, they proved that they were, at worst, capable starters that possessed the necessary drive to evolve into long-term fixtures. In 2016, they led their teams from 1-3 starts to the brink of playoff contention. Tampa Bay finished with its first winning season since 2010; Tennessee its first since 2011.Records fell along the way. Winston became the first quarterback in NFL history to pass for more than 4,000 yards in each of his first two seasons. He set the Bucs' record for touchdown passes in a single season (28). Mariota set the Titans' record, too, throwing 26 touchdowns in 15 games (he suffered a fractured fibula in Week 16). His eight straight games with multiple touchdown passes also was a team record.Like the highly touted prospects before them, Winston and Mariota will be linked together forever. We'll critique their throws, parse their words, debate their leadership. Every so often, we'll ask, "Who is better?"In 2015, the answer was Winston. This season? Mariota didn't just catch up to him — he passed him by, at least in the ways we can measure. To find out how, let's dive into the numbers.BASIC STATISTICS: ADVANTAGE MARIOTAYardage, touchdown and interception totals alone don't tell us much. They're an indication of volume, not efficiency.When we compare the two on a per-pass basis, Mariota is the front-runner. He gained more yards per pass, completed a higher percentage of his passes and a greater percentage of his passes resulted in touchdowns.The most glaring difference: turnovers. Last season, opponents intercepted Mariota and Winston at roughly the same rate. This season, Mariota's rate improved to above league average while Winston's worsened. Only Case Keenum, Philip Rivers and Ryan Fitzpatrick threw picks more frequently.Winston also lost more fumbles than he did in 2015. He was tied for the league league with six; Mariota had five.Winston has a Ben Roethlisberger-like knack for eluding defenders, extending plays and making something out of nothing. He refuses to surrender. It's a strength, but sometimes that mentality holds him — and the team — back.Consider the interception he threw at the beginning of the second half of the Bucs' Week 16 game against the Saints. On second and 11 from the 3-yard line, Tampa Bay, which was in max protection to prevent a sack, sent only two receivers out on routes. Winston locked in on Mike Evans, even though the cornerback covering him had safety help over the top. Seconds later, New Orleans celebrated a pivotal touchdown."No one was open," Winston said. "I tried to give my guy a chance."Mariota is quicker to give up on plays. In the Titans' comeback win over the Chiefs in Week 15, he intentionally threw a pass away three times. Each time, Tennessee gained a first down on the next play or the play after.• • •QUARTERBACK RATINGS: ADVANTAGE MARIOTAThe NFL's traditional quarterback rating is an imperfect statistic — it considers only five variables: attempts, completions, yards, touchdowns and interceptions — but it is correlated to winning. Both quarterbacks' ratings increased this season, with Mariota cracking the top 10.ESPN's Total QBR and Football Outsiders' Defense-adjusted Value Over Average strive to better represent a quarterback's efficiency. Unlike quarterback rating, QBR and DVOA weigh game situations and quality of opponents. A 5-yard completion on third and 5 against the Broncos in a tight game is different from a 5-yard completion on third and 15 against the Browns in a blowout.Among the differences between QBR and DVOA:• QBR incorporates a quarterback's value as a runner. The DVOA number cited here refers only to his value as a passer.• Because not all passes are the same (for example, a pass that travels 25 yards vs. a screen pass in which the receiver gains 25 yards after the catch), QBR divides credit on a play among a quarterback and his teammates.• QBR is expressed on a 0 to 100 scale. DVOA is expressed as a percentage. If a quarterback has a DVOA of 5 percent, that means he played 5 percent above league average.While QBR shows little separation between Winston and Mariota, DVOA favors the Titans quarterback. Mariota, who earned a minus-13.2 percent DVOA rating in 2015, improved by 22.5 percentage points. Winston improved by 1.6 points.• • •INTERMISSION: SEASON-DEFINING PLAYSThese highlights showcase Winston's and Mariota's competitiveness, as well as the danger they pose to defenses.Situation: Bears at Bucs, Week 10, third and 10 from the Tampa Bay 23Situation: Titans at Chargers, Week 9, second and 10 from the San Diego 14• • •PRESSURE STATISTICS: ADVANTAGE MARIOTATo evaluate each quarterback's performance under pressure, we'll look at not only how he performed against pass rushes but also how he performed in third-down situations, the plays that often decide whether drives continue or end.On third down, Mariota outplayed Winston, gaining more yards per attempt, completing a higher percentage of his passes and posting a higher quarterback rating. Mariota threw 11 touchdowns to three interceptions while Winston threw seven touchdowns to six interceptions.Almost every quarterback not named Aaron Rodgers struggles to maintain the same quality of play when pressured. Winston — who had nearly 100 more dropbacks under pressure than Mariota — completed a higher percentage of his passes, but his six interceptions to Mariota's two dragged on his quarterback rating, which was 2.6 points lower.• • •DEEP PASS STATISTICS: ADVANTAGE MARIOTABefore Mariota's NFL debut, his detractors suggested he was a system quarterback, that he would struggle throwing into tight windows. His ball placement was too inconsistent, they said.Last season, they were right. Mariota's 20.4 accuracy percentage (a Pro Football Focus formula that accounts for dropped passes, throwaways, spikes, batted passes and passes thrown while the quarterback is hit) on throws 20 or more yards down the field was the league's lowest.This season, he made significant strides toward erasing concerns about his deep ball. He nearly tripled his completions and yardage and doubled his touchdowns and accuracy percentage. His rating on deep passes improved from 32.8 to 101.2.The touch that had been missing from his throws in 2015 was on display throughout this season.There was his 29-yard touchdown pass to Rishard Matthews over the top of the Bears defense in Week 12.He did it against the league's best pass defense, too, when in Week 14 against the Broncos, he dropped a 23-yard dime to tight end Delanie Walker. The conversion on third and 5 was the precursor to the Titans' only touchdown of the game.The deep pass added a dimension to Tennessee's offense that didn't exist in 2015. In fact, the Titans jumped the Bucs, scoring more points per game and gaining more yards per play.As for Winston, his deep pass statistics this season weren't dissimilar from 2015, except in one regard. By now, you can predict the word that will follow the colon in this sentence: interceptions. Defenses intercepted only one of his 64 passes in 2015. This season, they intercepted six of his 69.Success on such plays depends upon more than the quarterback, of course. While the Bucs have one of the NFL's very best receivers in Mike Evans and an emerging weapon in tight end Cameron Brate, they lack a speed threat that can separate from defenses. Before we excuse Winston, though, let's acknowledge that the Titans' receiving corps of Rishard Matthews, Tajae Sharpe and Delanie Walker — while underappreciated — isn't exactly the second coming of Marvin Harrison, Reggie Wayne and Dallas Clark.Both the Titans and Bucs have set out to support their quarterbacks by investing in their offensive lines and ground attacks. Tennessee added DeMarco Murray and drafted Derrick Henry. Tampa Bay retained Doug Martin.Whether because of talent, luck or some combination thereof, Mariota and the Titans' offense are progressing more quickly than Winston and the Bucs' offense. That can change, however, as quickly as the next free agent signing or draft pick. If "Winston vs. Mariota I" taught us anything, it's this: It is wiser to let the process play out than it is to draw sweeping conclusions off early results.Statistics in this report are from Football Outsiders, Pro Football Focus and Pro Football Reference. Contact Thomas Bassinger at [email protected] Follow @tometrics.