The 2015 season for the Detroit Lions was truly a tale of two halves.

A terrible 1-7 start gave way to a terrific 6-2 finish as the Lions ended the year in the middle of the pack at 7-9, earning the 16th pick in the draft.

The halfway point of the season saw Jim Bob Cooter take over as offensive coordinator and Ron Prince as offensive line coach. There was also the firing of the team president and general manager along the way.

The schedule got a little easier the second half of the season, I'd be remiss not to mention that, but Detroit played a better brand of football. The statistics prove it:

No one's play saw a more dramatic rise from one level of the thermometer to the other than quarterback Matthew Stafford.

Over the first eight games, Stafford completed 193-of-299 passes (64.5 percent) for 2,083 yards with 13 touchdowns, 11 interceptions and a passer rating of 84.1.

In his last eight games, Stafford was 205-of-293 passing (69.9 percent) for 2,179 yards with 19 touchdowns, two interceptions and a passer rating of 110.1.

Stafford's 67.2-completion percentage for the year is a team record, and his 97.0 passer rating is second behind the 97.2 rating he recorded in 2011, when he threw for more than 5,000 yards and 41 touchdowns.

Stafford also got a little more help from the run game in the second half of the season.

The team registered just one 100-yard performance on the ground in the first eight weeks and had just 557 total yards on the ground (69 per game) heading into the bye week.

They rushed for at least 100 yards in five of their last eight contests and totaled 778 yards on the ground for a 97.3 average per game.

Rookie running back Ameer Abdullah averaged 3.6 yards per rush the first half of the season. That jumped all the way to 4.7 over the team's last eight games.

What about the other side of the ball?

Detroit's run defense was terrible the first half of the season and that might be understating it. They were allowing 133.8 yards per game and a 4.3 average at the midway point.

In the second half, that number dipped more than 40 yards per game to 91.8.

There were a number of individual efforts on defense that helped spur that unit into better play.

Tahir Whitehead, after playing a limited role to begin the season, was one of the most consistent performers the second half of the season. He finished the season with 50 tackles after having just 10 the first eight games.

Devin Taylor nearly doubled his sack total from 2.5 the first eight games to 4.5 in the final eight.

Cornerbacks Nevin Lawson and Quandre Diggs proved to be an upgrade at their positions and appear to have bright futures moving forward.

Safety Isa Abdul-Quddus earned a starting spot the second half of the season and proved to be a much better fit than James Ihedigbo at strong safety.

Even defensive tackle Haloti Ngata, after getting past some injuries the first half of the year, had more tackles, sacks and made a greater impact in the second half.

Here's a look at some other key stats – good and bad – after 17 weeks of football:

The top three offensive and defensive grades given out by Pro Football Focus in Sunday's win at Chicago:

Offense: WR Calvin Johnson ( 5.0), QB Matthew Stafford ( 1.6), RB Joique Bell ( 1.6)

Defense: DE Ziggy Ansah ( 2.4), LB Tahir Whitehead ( 2.2), DE Devin Taylor ( 1.9)

The bottom three offensive and defensive grades given out by Pro Football Focus in Sunday's win at Chicago:

Offense: TE Eric Ebron (-3.0), TE Bear Pascoe (-2.0), G Larry Warford (-1.7)

Defense: CB Quandre Diggs (-4.7), DT C.J. Wilson (-1.9), LB Josh Bynes (-0.6)

• Ziggy Ansah's plus-seven sack improvement from 2014 tied with Whitney Mercilus for the fifth-best sack increase from 2014 to 2015. Devin Taylor's plus six tied for 10th-best.
• Ansah's career high 14.5 sacks rank as the second highest single-season total (official since 1982), trailing only Porcher's 15.0 sacks in 1999.
• Detroit finished the season as the worst rushing football team in the NFL at 83.4 yards per game.
• K Matt Prater's* *59-yard field goal Sunday in Chicago set a new team record for the longest field goal in Lions history. It surpassed the previous record of 56 accomplished twice by K Jason Hanson (Cle 10/8/95; at Car 11/16/08).
• The Lions struggled to find consistency upfront along their offensive line most of the year, but especially in the first half of the season. Here are the final Pro Football Focus rankings of the five starters upfront for Detroit. LT Riley Reiff (17th among LTs), LG Laken Tomlinson (58th), C Travis Swanson (34th), G Larry Warford (46th) and RT Michael Ola (13th among RTs).
• WR Golden Tate's 90 catches ranks 10th all-time in the franchise's list for single-season receptions.
• With Tate (90), WR Calvin Johnson (88) and RB Theo Riddick (80) each reaching 80-plus catches, it marks the first time in team history that three teammates each finished with at least 80 catches apiece.
• Detroit's sack percentage per pass attempt of 8.0 was fourth best in the NFL.
• The Lions finished minus-six in turnover differential, which ranked 26th.
• S Glover Quin now has 11 interceptions over the past two seasons (second in NFL) and 14 since joining the Lions in 2013 (tied for first in NFL).
• P Sam Martin re-sets the team's single-season record with a 42.0 net punting average. Martin is the only Lions punter since net punting became an official statistic in 1976 that has finished with a 40.0 net punting average in a season, and he has accomplished this in each of his three NFL seasons.
• The Lions punt coverage team allowed 6.1 yards per punt return this season (sixth in the NFL), the club's lowest average since 2002 (4.5 yards).
• Rookie RB Ameer Abdullah's 29.1 kickoff return average in 2015 set a new single-season franchise record, breaking the previous high of 28.4 by Mel Gray in 1994. Abdullah finished second in the NFL in kickoff return average this season.
• Detroit's 7-9 record to finish the year is their 13th losing season in their last 15 seasons.