As six retired players and Dallas Cowboys owner Jerry Jones took their spots in the Pro Football Hall of Fame this weekend, legendary coaches remained on the sideline. This was the ninth time in the past 11 years that no coaches earned enshrinement. Seventy-three of 75 inductees over that span were not coaches, and with Don Coryell falling short as a finalist 31 years after coaching his final game, the guys responsible for motivating grown men could use a pep talk themselves.

There is hope. John Madden waited 28 years, Hank Stram waited 26 and George Allen waited 25, which reflects the process as much as anything. Coaches compete in the same category as players on the theory both made their marks at field level, unlike contributors. It's a debatable premise and a problem for coaches whose candidacies require some deliberation

Using research from Pro Football Reference and other sources, here are six former coaches whose candidacies deserve a closer look:

Marty Schottenheimer

Regular season: 200-126-1 (.613)

Playoffs: 5-13 (.278)

Super Bowls: none as a head coach

Where he ranks: seventh in regular-season victories, seventh in games above .500 (74), 33rd in postseason victories

What to know: The six coaches with more regular-season victories than Schottenheimer are all in the Hall of Fame or headed there (Bill Belichick). Those six also combined for 28 titles, including at least two apiece, and that is where Schottenheimer falls short.

Is 200 wins exceptional enough to get Schottenheimer into the Hall without even reaching a Super Bowl? A fair review must consider how much Schottenheimer was to blame for the incredible series of disasters that doomed his teams in the playoffs. There was The Drive, The Fumble, Lin Elliott's meltdown and Marlon McCree's fumble during what should have been a game-clinching fourth-down interception return off Tom Brady.

Heartbreaking defeats are part of the game for every coach, but some of these were especially cruel and even unlucky. For example, while data has shown that fumble recoveries are random, Schottenheimer's opponents recovered an incredible 15 of 15 fumbles in the games culminating with The Drive, The Fumble and McCree's miscue (hat tip: Jason Lisk of The Big Lead). While with Kansas City, Schottenheimer once lost a playoff game to Miami that hinged in part on fourth-quarter turnovers by Joe Montana (red zone interception) and Marcus Allen, Hall of Famers both.

Most great coaches had great quarterbacks. Schottenheimer typically did not. Three of the six coaches ahead of Schottenheimer in all-time wins -- George Halas, Curly Lambeau, Paul Brown -- coached before the NFL took a sharp turn toward becoming a passing league with rules changes enacted in 1978. The other three -- Don Shula, Tom Landry and Belichick -- enjoyed long associations with Hall of Fame quarterbacks. Bernie Kosar and Philip Rivers combined for three Pro Bowls with Schottenheimer, but a two-year stint with an aging Montana was Schottenheimer's only association with a truly great quarterback. Montana was 36 and 37 years old in his two seasons under Schottenheimer.

Schottenheimer wasn't just a compiler. He's also one of seven coaches with 300 games coached and a winning percentage of at least .600 (Andy Reid, who is becoming the Schottenheimer of this era unless he wins a title, has a chance to join the list this season).

Chuck Knox had a five-year stretch with the Rams during which they went 54-15-1 and never had a record worse than 10-4. Rick Stewart/Getty Images

Chuck Knox

Regular season: 186-147-1 (.558)

Playoffs: 7-11 (.389)

Super Bowls: none as a head coach

Where he ranks: 10th in regular-season victories, 26th in games above .500 (74), 28th in postseason victories

What to know: Knox was a four-time coach of the year who twice took over losing teams and brought them to the playoffs in his first season on the job.

Much like Schottenheimer, Knox won consistently in multiple places without having Hall of Fame quarterbacks on his side. While Schottenheimer was once fired following a 14-2 season in San Diego, Knox lost his job with the Rams after posting a 54-15-1 record in five seasons with the team. He won division titles all five years and never finished worse than 10-4 in any of them. He twice lost NFC title games to the great Minnesota teams of the 1970s in games that turned against Los Angeles on plays made inside the Vikings' 1-yard line.

Knox famously said upon taking the Rams job in 1972 that quarterback was just another position, but that became much less the case as time passed. While with Seattle, Knox got three Pro Bowl seasons from Dave Krieg in an era when his division rivals often had Dan Fouts and John Elway. His teams were not bad enough to secure the draft choices needed to select the most heralded quarterbacks. Though the details are in dispute, Knox reportedly wanted Seattle to draft Brett Favre in 1991, when the team selected Dan McGwire instead.

Bud Grant, Marv Levy and George Allen all made it to Canton as head coaches without winning a Super Bowl. Grant and Levy appeared in four apiece, seven of them with Hall of Fame quarterbacks.

There are three members of the 1990s-era Packers in the Hall of Fame. Will Mike Holmgren be joining them? Getty Images

Mike Holmgren

Regular season: 161-111 (.592)

Playoffs: 13-11 (.542)

Super Bowls: 1-2 as a head coach

Where he ranks: 16th in regular-season victories, 19th in games above .500 (50), sixth in postseason victories

What to know: Ron Wolf, Brett Favre and Reggie White were the first three 1990s Packers icons enshrined in the Hall. Holmgren would be a logical choice as the fourth pillar as a driving force behind turning around the franchise, especially considering his work before and after his time in Green Bay.

Holmgren guided two previously long-suffering franchises to the Super Bowl, winning once and losing twice. He did it by taking quarterbacks with varying pedigrees and molding them into Pro Bowl (and even MVP-caliber) performers within a specific offense for which he was the playcaller.

There were early indications when Holmgren was in San Francisco and Steve Young was a reclamation project under Bill Walsh and Holmgren. The trend continued when Holmgren's Packers acquired Favre, and when Holmgren personally acquired Matt Hasselbeck for Seattle. Favre became a three-time MVP. Hasselbeck became a three-time Pro Bowler. They combined to play 37 seasons in the NFL.

Holmgren's giant coaching tree is another consideration. Protégés Andy Reid, Jon Gruden, Steve Mariucci and Mike Sherman have combined to go 397-301-1 (.569) as head coaches.

Mike Shanahan coached Robert Griffin III to the QB's best season, on top of two Super Bowl victories with the Broncos. Dilip Vishwanat/Getty Images

Mike Shanahan

Regular season: 170-138 (.552)

Playoffs: 8-6

Super Bowls: 2-0 as a head coach

Where he ranks: tied for 14th in regular-season victories, 30th in games above .500 (32), tied for 25th in postseason victories

What to know: Shanahan's hiring as the Broncos' head coach and de facto GM was the impetus behind Denver finally breaking through as a Super Bowl champion (twice). Elway enjoyed his best seasons under Shanahan, who installed a proven offensive system while upgrading the talent around the Hall of Fame quarterback.

Shanahan obviously benefited from coaching Elway. The relationship was mutually beneficial. Elway tossed 199 touchdown passes with 177 interceptions in his first 12 seasons, including four with Shanahan as offensive coordinator. His TD-INT ratio was 101-55 with Shanahan as head coach. Shanahan's regular-season winning percentage with Elway (47-17, .734) was about what it was with Jake Plummer (39-15, .722) in the lineup. He went 27-24 (.529) with Brian Griese and turned running backs with modest draft-day pedigrees into high producers.

Shanahan's offense also helped turn Robert Griffin III into a dynamic force until a knee injury derailed his career. Shanahan's handling of Griffin leading up to that injury is something Hall selectors will navigate in considering his candidacy.

Shanahan, Schottenheimer and other well-known coaches have failed in Washington under owner Daniel Snyder. Shanahan fared well during his honeymoon period with Washington, and he was a leading reason the team used a fourth-round draft choice for Kirk Cousins. Shanahan's time in Denver proved how effective he could be with outstanding ownership and a top-tier quarterback.

Tom Coughlin's final seasons with the Giants weren't fantastic, but he did lead them to two epic Super Bowl victories. Al Bello/Getty Images

Tom Coughlin

Regular season: 170-150 (.531)

Playoffs: 12-7

Super Bowls: 2-0 as a head coach

Where he ranks: tied for 14th in regular-season victories, tied for 46th in games above .500 (20), tied for seventh in postseason victories

What to know: Coughlin, like Shanahan, is one of eight coaches with at least 150 regular-season victories and more than one Super Bowl title. Don Shula, Tom Landry, Chuck Noll, Bill Parcells and Joe Gibbs are already in the Hall of Fame. Belichick will also be there. That leaves Coughlin and Shanahan, who rank tied for sixth on that eight-man list with 170 victories.

Coughlin was not known for calling plays, introducing an innovative scheme, developing quarterbacks or producing an expansive coaching tree. He did quickly take the expansion Jacksonville Jaguars to the AFC title game. He also quickly made the Giants into a contender before leading them to gold-standard Super Bowl victories over New England.

The selection committee will have to determine whether those iconic Super Bowl victories and success with two franchises offsets the way Coughlin left both organizations. He was 13-29 in his final three seasons in Jacksonville and 13-29 in his final three with the Giants. He was 144-92 (.610) the rest of the time, and endured 20 years as a head coach, same as Shanahan.

Bill Cowher brought the Steelers to the Super Bowl on two occasions, with nine years in between. John David Mercer/USA TODAY Sports

Bill Cowher

Regular season: 149-90-1 (.623)

Playoffs: 12-9

Super Bowls: 1-1 as a head coach

Where he ranks: 20th in regular-season victories, tied for 14th in games above .500 (59), tied for seventh in postseason victories

What to know: Ben Roethlisberger became a top-tier quarterback, but he was not one when Cowher was coaching him. That means Cowher took the Steelers to two Super Bowls with two different below-top-tier quarterbacks. Cowher also took two very different teams to the biggest stage, with nine years in between those Super Bowl runs. His Steelers reached six AFC title games during his 15-year run as head coach.