In the 23 years since the NFL adopted unfettered free agency for players in 1993, the Lions have signed players across the board to fix and upgrade holes in the roster.

Like all teams, they've had mixed results.

On the positive side of the ledger, they signed 1,000-yard rushers (James Stewart and Reggie Bush), Pro Bowl defensive backs (cornerback Dre Bly and safety Glover Quin), and linemen on both sides of the ball who came in as instant starters.

In other cases, players failed to produce up to expectations.

With the 2016 free-agent market already in full swing, here is a look at the Detroit Lions all-time free agent team. It differs from some previous all-time teams because it picks the best free agents on offense, defense and the specialists signed by the Lions as opposed to a top 10, regardless of position.

There are a few rules in the all-time free-agent team. Veteran players had to be signed as free agents in the offseason. That eliminates from consideration players who have been cut and signed during the season.

In some cases, impact for a short period of time outweighs long-term production.

One rule is being stretched beyond the 1993-2015 qualifying dates to include a special player.

Also, veterans who were acquired in trades in the offseason are not included. That eliminates players such as guard Rob Sims, a five-year starter acquired in a 2010 trade with Seattle, and backup quarterback Shaun Hill, also acquired in a 2010 trade with San Francisco.

The first installment is the all-offense team.

As always, feel free to disagree.

Quarterback, starter: Scott Mitchell (1994-98) -- The fans didn't like him, but he was the first Lions QB to pass for 4,000 yards in a season (4,338, 32 TDs) in 1995. He was the opening-day starter for five straight years. He was benched after two games in 1998 and never played again for the Lions.

Quarterback, backup: Dave Krieg (1994): His impact in seven starts was magical. Krieg rescued the '94 season when he finished out a loss to Green Bay in Game 9 after Mitchell went out with a season-ending injury.

At the age of 36, and in the 15th of his 19 pro seasons, Krieg had a 5-2 record as a starter with 14 TD passes, three interceptions and a passer rating of 101.7 to lead the Lions to a playoff berth as a wild card.

Other QBs: Jon Kitna (starter, 2006-08); Gus Frerotte (backup, 1999); Don Majkowski (backup, 1995-96); Frank Reich (backup, 1997-98).

Running back: James Stewart (2000-03) -- He had two 1,000-yard rushing seasons, starting with 1,184 yards and 10 TDs in his first season in Detroit. A shoulder injury in a 2003 preseason game ended his career.

Other RBs: Reggie Bush (2013-14) is a close second to Stewart because he was a 1,000-yard runner in 2013 and a big-play contributor in a limited role on the 2014 playoff team; Shawn Bryson (2003-06).

Fullback: Tommy Vardell (1997-98) -- Converted from tailback to fullback in Detroit, Vardell made himself an efficient blocker and short-yardage runner. Vardell blocked for Barry Sanders when he rushed for 2,053 yards in 1997, and he scored 12 touchdowns in his two seasons in Detroit.

Other FBs: None qualify.

Wide receiver: Golden Tate (2014-15) -- Perhaps the Lions' best free-agent signing ever. He had 99 catches and made the Pro Bowl in 2014 and 90 catches in 2015. He's tough, sure-handed and elusive in the open field and in traffic.

Wide receiver: Nate Burleson (2010-13) -- He knew his role as a complement to Calvin Johnson and played it well when healthy. He was the best kind of leader. It came naturally.

Other WRs: Az-Zahir Hakim (2002-06); Mike Furrey (2006-08); Shaun McDonald (2007-08); Lance Moore (2015).

Tight end: Marcus Pollard (2005-06) -- He came to the Lions after 10 seasons with the Colts and Peyton Manning and upgraded the tight end position immediately with 46 catches. After being phased out in 2006 he departed.

Other TEs: Stephen Alexander (2004); Pete Metzelaars (1996-97); Rodney Holman (1993-95).

Guard: Ray Brown (2002-03) -- He was 40 when he signed with the Lions but still had four seasons left. He started all 32 games in two seasons with the Lions and played his best ball against good teams.

Guard: Damien Woody (2004-07) -- There was no question about his ability, but weight problems and injuries limited his effectiveness. Eventually he moved to tackle, where he was an even larger presence.

Tackle: Ray Roberts (1996-2000) -- He had the unenviable job of replacing Lomas Brown when Brown left in 1996 as a free agent. Roberts was steady, starting 70 games in five seasons while fighting injuries that ended his career early.

Tackle: Dave Lutz (1993-95) -- Lutz was part of a trio of offensive linemen signed in 1993 – the first year of free agency -- to rebuild the offensive line. Lutz played right tackle for two years and right guard for one. He was a massive man who helped the Lions make the playoffs all three seasons he was in Detroit.

Center: Jim Pyne (1998) – The longevity the Lions have had at center makes Pyne the only center between Kevin Glover (1985-97) and Dominic Raiola (2001-04) who qualifies as a free agent signed in the offseason. After one undistinguished season in Detroit, Pyne went to Cleveland in the 1999 expansion draft.

Other OL: T Zefross Moss (1995-95); G Dave Richards (1993); G Bill Fralic (1993); G Edwin Mulitalo (2007-08).

Kicker: David Akers (2013) -- The presence of Jason Hanson from 1992 through 2012 left no opportunity to sign a free-agent kicker until Hanson retired. Akers was adequate in his one season in Detroit, which proved to be the last in a fine career in which he made the Pro Bowl six times.

Return man: Mel Gray (1989-94) -- Special player and special circumstances require special rules to include Gray on any team of Lions' best free-agent signings. The NFL adopted Plan B free agency in 1989, and the Lions signed Gray when the Saints failed to make him one of the 37 players on their protected list.

In six seasons as a Lion Gray made the Pro Bowl four times, was first-team All Pro three times and scored seven touchdowns on returns.