© Tim Heitman-USA TODAY Sports

Micah Parsons is the piece that transformed the Dallas Cowboys defense from one of the worst in the NFL to one of the best. Prior to the Cowboys selecting Parsons with the 12th overall pick in the NFL Draft, Dallas finished with the 28th ranked defense in points allowed and 23rd in yards allowed. This season, the Cowboys are seventh in points allowed and 19th in yards allowed -- a huge reason why the team clinched the NFC East and is a Super Bowl contender at 11-4. 

Parsons has been a force for the Cowboys since Day 1, recording 79 tackles, 13 sacks, three forced fumbles and three passes defensed while lining up as an edge rusher and a linebacker for the Cowboys. He has 45 pressures and 29 quarterback hits, both ranking in the top three for all defensive players. 

Just 15 games into his career, Parsons has already established himself as one of the top defensive players in the game. Not only his Parsons the front runner for defensive rookie of the year, he's a contender for Defensive Player of the Year. 

In this week's "By The Numbers," we're taking a dive into Parsons' rookie season and where he ranks with the best defensive rookies in NFL history. 

NFL leaders -- sacks

  1. T.J. Watt (Steelers) -- 17
  2. Robert Quinn (Bears) -- 17
  3. Nick Bosa (49ers) -- 15
  4. Myles Garrett (Browns) -- 15
  5. Trey Hendrickson (Bengals) -- 14
  6. Micah Parsons (Cowboys) -- 13

NFL leaders -- QB hits

  1. T.J. Watt (Steelers) -- 31
  2. Nick Bosa (49ers) -- 30
  3. Micah Parsons (Cowboys) -- 29
  4. Myles Garrett (Browns) -- 29
  5. Jonathan Allen (Washington) -- 27 

NFL leaders -- Pressures

  1. Nick Bosa (49ers) -- 46
  2. Myles Garrett (Browns) -- 46
  3. Micah Parsons (Cowboys) -- 45
  4. T.J. Watt (Steelers) -- 42
  5. Matt Judon (Patriots) -- 42
  6. Trey Hendrickson (Bengals) -- 42

*Per Pro Football Reference

What Parsons has been able to accomplish in his rookie season is incredible. Parsons had 9.5 sacks in a six-game stretch (his six-game sack streak), which was the most for a rookie in league history for that many games. He's one of just five players with 13 sacks and three forced fumbles this season, joining Watt, Quinn, Bosa, and Hendrickson. 

Parsons has the second highest pressure rate of any defender in the league at 21.6% (per Pro Football Focus), trailing only Devin White (25.9%). His 10.3% run-stop rate is fourth highest in the NFL, trailing only Denzel Perryman, Nick Bolton, and teammate Leighton Vander Esch

What makes Parsons dominant is his ability to play nearly any position on defense. Parsons has played 454 snaps at linebacker, 347 on the defensive line, 25 at cornerback, and one at safety -- making him one of the most versatile players in the NFL. The Cowboys were a top-10 defense in takeaways prior to Parsons, yet he's made them No. 1 in the NFL in that department. 

How does Parsons' rookie campaign compare to the all time greats?

Most sacks by a rookie -- NFL history

  1. Jevon Kearse (Titans, 1999) -- 14.5
  2. Aldon Smith (49ers, 2011) -- 14
  3. Dwight Freeney (Colts, 2002) -- 13
  4. Micah Parsons (Cowboys, 2021) -- 13
  5. Reggie White (Eagles, 1985) -- 13

*Sacks became an official stat in 1982

Most QB hits by a rookie -- NFL history 

  1. Micah Parsons (Cowboys, 2021)-- 29
  2. Von Miller (Broncos, 2011) -- 29
  3. Aldon Smith (49ers, 2011) -- 27
  4. Kamerion Wimbley (Browns, 2006) -- 26
  5. Nick Bosa (Browns, 2019) -- 25

*QB hits became an official stat in 2006

Most tackles for loss by a rookie -- NFL history

  1. Kendrell Bell (Steelers, 2001) -- 23
  2. Lavonte David (Buccaneers, 2012) -- 20
  3. Dwight Freeney (Colts, 2002) -- 20
  4. Von Miller (Broncos, 2011) -- 19
  5. Micah Parsons (Cowboys, 2021) -- 18
  6. Aaron Donald (Rams, 2014) -- 18

*TFL became an official stat in 1999

Parsons could hold all three of these marks by season's end, and has two games to get two sacks and six tackles for loss. He already has the most quarterback hits ever for a rookie, which showcases his dominance given he's only played 15 games. Parsons is the sixth player since tackles for loss became an official stat in 1999 to have at least 12 sacks and 16 tackles for loss in his rookie campaign -- and is the only player to reach those marks in his first 14 games. Parsons and Dwight Freeney are the only rookies in league history to have 13 sacks and 18 tackles for loss in their first season. 

Parsons is one of just eight players in NFL history to have totaled 13 sacks, 75 tackles, three passes defensed and three forced fumbles in the same season -- and the first rookie to ever accomplish the feat. If Parsons notches one more quarterback hit and gets to 30, he'll join J.J. Watt as the only players on this list to have those numbers -- and 30 quarterback hits (since quarterback hits were first tracked in 2006). 

Not only is Parsons setting new rookie benchmarks for the league, he's also rewriting the Cowboys record book. Parsons' 6.5 sacks in November are the most in a single month in Cowboys history for a rookie and he has three multi-sack games in his first NFL season -- the most such games by any Cowboys rookie in team history. 

Harvey Martin is the only Cowboys player ever to win Defensive Player of the Year (1977). Based on the impact Parsons has made to the Cowboys defense and how he stacks up amongst the best players in the game, he may be holding that trophy in seven weeks.