The is the win record differentials for many long term starters that came into the league in 1980s.
Dan Marino
| Seasons | Teams | Record | Projected | +/- | Context |
| 1983 | MIA | 7-2 | 5.77-3.23 | 1.23 | C Stephenson made all-pros from 1983- 1987, G Kuechenberg made a pro bowl, WR Duper made a pro bowl, G Newman made an all-pro. |
| 1984 | MIA | 14-2 | 8.71-7.29 | 5.29 | G Kuechenberg retired, WR Duper made a pro bowl, WR Clayton made an all-pro, G Newman made an all-pro |
| 1985 | MIA | 12-4 | 7.38-8.62 | 4.62 | 5 game-winning drives, G Newman retired but replaced by G Foster and he made a pro bowl, WR Duper missed 8 games, WR Clayton made a pro bowl. |
| 1986 | MIA | 8-8 | 6.24-9.76 | 1.76 | G Foster made a pro bowl, WR Duper made a pro bowl, WR Clayton made a pro bowl. |
| 1987 | MIA | 7-5 | 5.14-6.86 | 1.86 | WR Clayton missed 4 games, WR Duper missed 5 games and declines moving forward, G Foster regressed and missed 4 games. |
| 1988 | MIA | 6-10 | 6.83-9.17 | -0.83 | C Stephenson retired, WR Clayton made a pro bowl. |
| 1989 | MIA | 8-8 | 6.83-9.17 | 1.17 | Gary Stevens became the offensive coordinator, barely above average despite 4 game-winning drives, TE Edmunds made a pro bowl although he wasn’t that great this yr and next. |
| 1990 | MIA | 12-4 | 10.57-5.43 | 1.43 | WR Clayton missed 6 games, TE Edmunds made a pro bowl, LT Webb made a pro bowl |
| 1991 | MIA | 8-8 | 8.00-8.01 | 0.00 | WR Duper is productive, WR Clayton made a pro bowl, LT Webb made a pro bowl |
| 1992 | MIA | 11-5 | 8.59-7.41 | 2.41 | 6 game-winning drives, LT Webb made all-pros from 1992-1995, WR Clayton regressed but TE Jackson arrived and made all-pro. |
| 1993 | MIA | 4-1 | 3.37-1.63 | 0.63 | Fryar arrived and made a pro bowl, FB Byars made a pro bowl, G Simms made a pro bowl |
| 1994 | MIA | 10-6 | 7.87-8.13 | 2.13 | WR Clayton retired, WR Fryar made an all-pro, G Simms made an all-pro |
| 1995 | MIA | 9-5 | 7.23-6.77 | 1.77 | TE Jackson left, G Simms made a pro bowl, WR McDuffie is productive from 1995-1998 |
| 1996 | MIA | 7-6 | 6.84-6.16 | 0.16 | Head coach Don Shula left and replaced by Jimmy Johnson, Gary Stevens stayed as the offensive coordinator, Only 1 game-winning drive, WR Fryar left, LT Webb made a pro bowl |
| 1997 | MIA | 9-7 | 8.23-7.77 | 0.77 | G Simms missed a lot of games, RT Brown is productive. |
| 1998 | MIA | 10-6 | 9.51-6.49 | 0.49 | Gary Stevens is replaced by Kippy Brown as the offensive coordinator, Only 1 game-winning drive, G Simms left, LT Webb missed 7 games |
| 1999 | MIA | 5-6 | 3.74-7.26 | 1.26 | Marino missed 5 games, WR Martin was productive |
Joe Montana
| Seasons | Teams | Record | Projected | +/- | Context |
| 1979 | SF | 0-1 | 0.76-0.24 | -0.76 | on the bench |
| 1980 | SF | 2-5 | 2.21-4.79 | -0.21 | started later in the year |
| 1981 | SF | 13-3 | 10.24-5.76 | 2.76 | WR Dwight Clark made a pro bowl, G Cross made an all-pro |
| 1982 | SF | 3-6 | 3.79-5.21 | -0.79 | Montana missed half the season, WR Clark made an all-pro, G Cross made a pro bowl, WR Solomon missed half the season |
| 1983 | SF | 10-6 | 8.52-7.48 | 1.48 | FB/RB Roger Craig is drafted, WR Solomon continued to regressed |
| 1984 | SF | 14-1 | 9.50-5.50 | 4.50 | RT Fahnhorst and G Cross made an all-pro, RB Craig is productive, RB Tyler made a pro bowl, C Quillan made a pro bowl. |
| 1985 | SF | 9-6 | 8.56 6.44 | 0.44 | Only 1 game winning drive, C Quillan made a pro bowl, RB Craig made an all-pro, TE Francis is productive from 1985-1986 |
| 1986 | SF | 6-2 | 5.63 2.37 | 0.37 | Only 1 game winning drive, G Cross made all-pro, WR Rice emerged in his 2nd year and made an all-pro, WR Solomon retired |
| 1987 | SF | 10-1 | 6.08 4.92 | 3.92 | RB Craig made a pro bowl, WR Rice won offensive player of the year, RT Fahnhorst missed most of the season, WR Clark regressed |
| 1988 | SF | 8-5 | 7.51 5.49 | 0.49 | WR Rice continued making all-pro from 1988-1990, RB Craig made an all-pro, RT Fahnhorst and WR Clark retired, WR Taylor technically made a pro bowl |
| 1989 | SF | 11-2 | 7.41 5.59 | 3.59 | 5 game winning drives, Offensive minded head coach Bill Walsh left and replaced by defensive minded head coach Seifert, Mike Holmgren became the offensive coordinator, WR Taylor made all-pro, RB Craig made a pro bowl, G McIntyre made pro bowls from 1989-1993 including an all-pro in 1992. |
| 1990 | SF | 14-1 | 9.66 5.34 | 4.34 | 5 game winning drives |
| 1991 | SF | 0-0 | 0-0 | 0 | did not start due to injury |
| 1992 | SF | 0-0 | 0-0 | 0 | did not start due to injury |
| 1993 | SF | 8-3 | 6.32 4.68 | 1.68 | had a defensive minded head coach Marty Schottenheimer, Paul Hackett was the offensive coordinator, LT Alt made a pro bowl, RB Allen made a pro bowl. |
| 1994 | SF | 9-5 | 8.90 5.10 | 0.10 |
John Elway
| Seasons | Teams | Record | Projected | +/- | Context |
| 1983 | DEN | 4-6 | 5.25-4.75 | -1.25 | 1 game winning drive |
| 1984 | DEN | 12-2 | 9.51-4.49 | 2.49 | John Hadl is no longer the offensive coordinator, RB Winder made a pro bowl, WR Watson is productive |
| 1985 | DEN | 11-5 | 7.91-8.09 | 3.09 | 6 game winning drives, Mike Shanahan becomes the offensive coordinator, WR Watson is productive |
| 1986 | DEN | 11-5 | 8.44-7.56 | 2.56 | 1 game winning drive, RB Winder made a pro bowl, G Bishop made a pro bowl |
| 1987 | DEN | 8-3 | 5.79-6.21 | 2.21 | G Bishop made a pro bowl, Watson decline and did not play much before leaving after this year |
| 1988 | DEN | 8-7 | 7.99-7.01 | 0.01 | only 1 game winning drive, Mike Shanahan is no longer the offensive coordinator, WR Vance Johnson is productive |
| 1989 | DEN | 10-5 | 9.62-5.38 | 0.38 | WR Johnson is productive, RB Bobby Humphrey was drafted and productive |
| 1990 | DEN | 5-11 | 6.26-9.74 | -1.26 | Chan Gailey takes over as the offensive coordinator, RB Humphrey made a pro bowl |
| 1991 | DEN | 12-4 | 10.91-5.09 | 1.09 | Mike Shanahan becomes the offensive coordinator again, WR Johnson no longer starting and regressed, RB Green arrived and made a pro bowl |
| 1992 | DEN | 8-4 | 6.22-5.78 | 1.78 | Shanahan is replaced by George Henshaw, RB Humphrey left, TE Sharpe emerged and made a pro bowl |
| 1993 | DEN | 9-7 | 9.07-6.93 | -0.07 | only 1 game winning drive, Head coach Reeves is replaced by defensive head coach Wade Phillips, RB Green left, TE Sharpe made an all-pro, LT Zimmerman arrived and made a pro bowl |
| 1994 | DEN | 7-7 | 5.86-8.14 | 1.14 | 4 game winning drives, TE Sharpe made a pro bowl, LT Zimmerman made an all-pro, WR Miller is productive |
| 1995 | DEN | 8-8 | 6.80-9.20 | 1.20 | Defensive minded head coach Wade Philips is replaced by offensive minded head coach Mike Shanahan, TE Sharpe made all-pros from 1995-1998, LT Zimmerman made an all-pro, WR Miller made a pro bowl, RB Davis was drafted and was productive |
| 1996 | DEN | 13-2 | 9.40-5.60 | 3.60 | 4 game winning drives, RB Davis won offensive player of the year, LT Zimmerman made an all-pro |
| 1997 | DEN | 12-4 | 8.44-7.56 | 3.56 | WR Miller left, RB Davis made an all-pro, C Nalen made a pro bowl from 1997-1998, WR Rod Smith emerged and was very productive |
| 1998 | DEN | 10-2 | 4.93-7.07 | 5.07 | RB Davis won MVP, G Schlereth made a pro bowl, WR Ed McCaffrey made an all-pro, WR Smith was very productive, LT Zimmerman left |
Jim Kelly
| Seasons | Teams | Record | Projected | +/- | Context |
| 1983 | N/A | 0-0 | 0-0 | 0 | not in the NFL |
| 1984 | N/A | 0-0 | 0-0 | 0 | not in the NFL |
| 1985 | N/A | 0-0 | 0-0 | 0 | not in the NFL |
| 1986 | BUF | 4-12 | 7.03-8.97 | -3.03 | 0 game winning drives, had head coach Marv Levy during his whole time in Buffalo |
| 1987 | BUF | 6-6 | 5.57-6.43 | 0.43 | |
| 1988 | BUF | 12-4 | 10.49-5.51 | 1.51 | 5 game winning drives. RB Thurman Thomas is drafted and is productive, WR Reed made a pro bowl, C Hull made all-pros from 1988-1991 |
| 1989 | BUF | 6-7 | 6.02-6.99 | -0.01 | Marchibroda replaced Ringo as OC, WR Reed and RB Thomas made an all-pro |
| 1990 | BUF | 12-2 | 8.59-5.41 | 3.41 | 0 game winning drives but had played really well regardless, the K-gun offense was debuted later in the season, WR Reed and RB Thomas made an all-pro, LT Wolford made a pro bowl |
| 1991 | BUF | 13-2 | 7.30-7.70 | 5.70 | 4 game winning drives, RB Thomas won MVP, WR Reed made pro bowls from 1991-1994, WR Lofton made a pro bowl, G Ritcher made an all-pro |
| 1992 | BUF | 11-5 | 8.95-7.05 | 2.05 | Bresnahan replaced Marchibroda as the OC, RB Thomas made an all-pro, LT Wolford, G Ritcher, and RT Ballard made a pro bowl |
| 1993 | BUF | 12-4 | 11.35-4.65 | 0.65 | 4 game winning drives but was still average, LT Wolford and WR Lofton left, RB Thomas made an all-pro, RT Ballard made a pro bowl, TE Metzelaars was productive, G Ritcher missed 6 games and regressed, WR Brooks is productive |
| 1994 | BUF | 7-7 | 6.18-7.83 | 0.82 | 1 game winning drives, RT Ballard and G Ritcher left, RB Thomas is productive |
| 1995 | BUF | 10-5 | 7.03-7.97 | 2.97 | RB Thomas regressed a bit, WR Reed missed most of the game |
| 1996 | BUF | 8-5 | 7.18-5.82 | 0.82 | 4 game winning drives, G Reuben Brown made a pro bowl, WR Reed is productive |
Randall Cunningham
| Seasons | Teams | Record | Projected | +/- | Context |
| 1985 | PHI | 1-3 | 2.38-1.63 | -1.38 | not the primary starter this yr and next, WR Quick made all-pro |
| 1986 | PHI | 1-3 | 2.64-2.36 | -1.64 | defensive minded head coach Bud Ryan replaced Campbell as the head coach, WR Quick made a pro bowl |
| 1987 | PHI | 7-5 | 4.14-6.86 | 2.86 | WR Quick made a pro bowl |
| 1988 | PHI | 10-6 | 7.54-8.46 | 2.46 | WR Quick missed half the season, TE Jackson made all-pro from 1988-1990 |
| 1989 | PHI | 11-5 | 9.69-6.31 | 1.31 | 5 game winning drives but was only a game above average, WR Carter was somewhat productive |
| 1990 | PHI | 10-6 | 8.26-7.74 | 1.74 | Kotite replaced Plum as the OC, WR Carter left, WR Quick continued to regress |
| 1991 | PHI | 1-0 | 0.94-0.06 | 0.06 | missed basically the whole season, offensive minded head coach Kotite replaced Ryan as the head coach, WR Quick retired. |
| 1992 | PHI | 10-5 | 9.25-5.75 | 0.75 | TE Jackson left, RB Herschel Walker was productive, WR Barnett made a pro bowl |
| 1993 | PHI | 4-0 | 1.39-2.61 | 2.61 | WR Barnett missed most of the season |
| 1994 | PHI | 7-7 | 7.42-6.58 | -0.42 | WR Barnett was productive |
| 1995 | PHI | 1-3 | 1.12-2.88 | -0.12 | didn’t play most of the season, RB Watters arrived and made a pro bowl |
| 1996 | N/A | 0-0 | 0-0 | 0 | Retired |
| 1997 | MIN | 1-2 | 1.10-1.90 | -0.10 | wasn’t primary starter, had head coach Dennis Green, LT Steussie and G McDaniel made all-pros, RB Robert Smith was productive, WR Carter made a pro bowl |
| 1998 | MIN | 13-1 | 7.50-6.50 | 5.50 | LT Steussie and G McDaniel made all-pros, WR Randy Moss was drafted and made an all-pro, RB Smith and WR Carter made a pro bowl, C Christy made all-pro. |
| 1999 | MIN | 2-4 | 3.07-2.93 | -1.07 | didn’t finished the last 10 games, Brian Billick left/ Ray Sherman replaced him as the OC, G McDaniel and C Christy made a pro bowl, WR Carter made an all-pro, WR Moss made a pro bowl |
| 2000 | DAL | 1-2 | 1.09-1.92 | -0.09 | had Dave Campo as the head coach, a backup moving forward, G Allen made an all-pro |
| 2001 | BAL | 2-0 | 1.46-0.54 | 0.54 | had offensive minded Billick as the head coach, T Ogden made an all-pro, TE Sharpe made a pro bowl |
Warren Moon
| Seasons | Teams | Record | Projected | +/- | Context |
| 1978 | N/A | 0-0 | 0-0 | 0 | not in the NFL |
| 1979 | N/A | 0-0 | 0-0 | 0 | not in the NFL |
| 1980 | N/A | 0-0 | 0-0 | 0 | not in the NFL |
| 1981 | N/A | 0-0 | 0-0 | 0 | not in the NFL |
| 1982 | N/A | 0-0 | 0-0 | 0 | not in the NFL |
| 1983 | N/A | 0-0 | 0-0 | 0 | not in the NFL |
| 1984 | HOU | 3-13 | 4.07-11.93 | -1.07 | G Munchack made a pro bowl, WR Tim Smith was productive |
| 1985 | HOU | 4-10 | 5.10-8.90 | -1.10 | defensive head coach Glanville replaced Hugh Campbell, G Munchack made an all-pro, WR Drew Hill made a pro bowl |
| 1986 | HOU | 5-10 | 7.03-7.98 | -2.03 | 0 game winning drives, Jamieson replaced Faragali as the OC, WR Hill was productive, G Munchack missed most of the season |
| 1987 | HOU | 7-5 | 4.05-7.95 | 2.95 | G Munchack made all-pros from 1987-1993, RB Rozier made a pro bowl |
| 1988 | HOU | 7-4 | 4.98-6.03 | 2.03 | only 1 game winning drive, technically no officially named OC, RB Rozier and WR Hill made a pro bowl, G Matthews made all-pros from 1988-1993 |
| 1989 | HOU | 9-7 | 5.85-10.15 | 3.15 | Gilbride took over as the OC, RB Rozier regressed and missed games, WR Hill was productive |
| 1990 | HOU | 8-7 | 8.60-6.40 | -0.60 | only 1 game winning drive, RB Rozier traded during the season, WR Hill made a pro bowl, WR Givens made all-pro, WR Jeffries was productive |
| 1991 | HOU | 11-5 | 10.09-5.92 | 0.92 | 5 game winning drives, WR Hill and WR Givens are productive, WR Jeffries made all-pro |
| 1992 | HOU | 6-4 | 5.60-4.40 | 0.40 | WR Hill left but WR Duncan, WR Givens and WR Jeffries all made a pro bowl, RB Lorenzo White made a pro bowl |
| 1993 | HOU | 12-4 | 9.97-6.03 | 2.03 | only 1 game winning drive, WR Jeffries and WR Slaughter made a pro bowl, RB White regressed and missed half the season but RB was productive |
| 1994 | MIN | 9-6 | 7.54-7.46 | 1.46 | 5 game winning drives, had Dennis Green as the head coach, WR Carter made all-pros, G McDaniel made all-pros from 94-98, WR Reed was productive, RB Terry Allen was productive |
| 1995 | MIN | 8-8 | 6.43-9.58 | 1.58 | WR Carter made a pro bowl from 1995-1997, WR Reed was productive from 1995-1997 |
| 1996 | MIN | 4-4 | 4.62-3.38 | -0.62 | |
| 1997 | SEA | 7-7 | 6.51-7.50 | 0.50 | 4 game winning drives, had head coach Erickson, RB Galloway was productive |
| 1998 | SEA | 4-6 | 5.76-4.24 | -1.76 | 0 game winning drives |
| 1999 | KC | 0-0 | 0-0 | 0 | backup moving forward |
| 2000 | KC | 0-1 | 0.53-0.47 | -0.53 |
Analysis
Contrary to what some may think, Marino’s defensive support ranged from being sub-mediocre at worst and solid at best. For almost all of his career, the average quarterback would have finished with a .500 win percentage, specifically estimated at 8-8 or 9-7 on the seasons that Marino started all 16 games. His worst defensive support that is considered sub-mediocre was from 1986 to 1989 in which the average quarterback would have gone two games under .500 in those seasons. His best defensive year was in 1990 in which the average quarterback would have won close to 11 games that season in a 16 game schedule.
1984 and 1985 were Marino’s only two great seasons as he won 4+ games above average. For the rest of his career, he was basically average or ranged from 1 to close to 2 games above average in terms of wins. Prior to his last few seasons, he basically had at least a couple of pro bowl to all-pro level offensive players, usually from any of the positions on that side of the ball outside of running back. He never had star production from a running back in any of his seasons. Other than 1984 and 1985, Marino never had a season with at least 3 wins above average despite usually having at least a couple stars on the offensive line and receiver.
With added context, Marino’s great 2-year stretch in his first few years can be attributed to him having a quick release and a great arm to execute the passing system that could attack base defenses of that era with the situation he had. It took the league a few years to adjust to Marino by implementing more nickel and dime coverages. Marino was susceptible to not having an impressive record differential whenever his supporting cast got worse or had long injuries. An example is how he was below average by almost a game in 1988 following the early retirement of center Stephenson. We do not know how having a star running back could have impacted Marino’s record differential. Overall, Marino had many solid record differential seasons of winning between 1-2 games above average, but he never had a great season outside of the 2-year stretch early in his career before defenses adjusted to him.
When he was the primary starter, Joe Montana basically had strong defensive support for his entire career with the expectation of 1980 and 1982. The average quarterback would have won 2+ games over .500 in almost every year of Montana’s career. A factor that has impacted Montana’s record differential is in how he struggled to stay healthy. There were seasons in which he failed to play the complete 16 game schedule and would often miss a few games on multiple occasions. Montana missing two seasons due to injuries later in his career also impacted his regular season career record differential. It took away opportunities to maybe achieve a higher record differential had he won those games since the game still get counted when calculating his average.
Durability is part of an athlete’s value. Montana missing games puts pressure on his teams to be able to win games with a backup to hopefully stay in the playoff race. His teams’ ability to do so gives him the opportunity to play in postseason games when he returns. Not every quarterback is afforded that opportunity. When Aaron Rodgers missed games in 2017, he returned for one game and when the Packers lost, they were eliminated. Had the team had a better record when he was out, the margin of error to make the playoffs would have been wider by the time he returned and would have given him another opportunity to compete in the postseason.
For almost all of Montana’s career, he always had a few stars on the offensive line and skill position group. With added context, Montana did also benefit from Bill Walsh’s West Coast offense and the same system was kept even after the coach left. Also, Montana’s offensive coordinator in the Chiefs ran the same West Coast offense. As a result, he never played in a different offensive system altogether whether it would have affected his ability to produce a good record differential or not. However, the west coast offense had been around with Bill Walsh for a decade before Montana took over. Montana’s peaks on the 49ers did show that he brought forth a higher ceiling for the offense than what it had been before. Also, he showed in 1989 that he was still capable of having great seasons even with offensive-minded head coach Bill Walsh retiring as Montana won over 3 games above average.
Despite having consistent offensive help and nice looking statistics, Montana’s record differentials fluctuated for most of the 1980s with being 3+ in some seasons, but then basically average such as having a record differential of .49 even when accounting for games missed due to injury. The low record differential seasons can be attributed to him not winning more games in which the defense gave up 26+ points and or even losing a few games when they would hold teams to under 15 points. An example is in 1988, in which he only went 3-2 when his defense gave up 10 points or fewer. He won those at a 60% win rate, which is considerably lower than the 93% win that an average would have had under those circumstances. He didn’t have a win enough difficult defensive scoring games to make up the difference when averaging it out. Montana’s record differential in the regular season averaged to only be a little over a game above average, primarily due to missed games due to injury as well as fluctuations in seasonal record differentials that can be around 3-4 games above average or as low as basically average.
During the 1980s, Elway mostly had good defensive support as there were many seasons in which the average quarterback would have finished around .500 in win percentage and a few seasons with a win-loss gap of over 2 games. In the 1990s, there was more fluctuation with Elway’s defensive support. His defense would have some pretty seasons, but then also some sub-mediocre to bad ones in which the average would have finished approximately 2-3 games below .500 in those situations, respectively. Despite Elway having statistics that did not look good in the 1980s, he some good record differential seasons in which he finished 2+ games above average. In some cases, it was mostly due to game winning drives, but also accumulating a good number of victories in some of the higher defensive points allowed brackets. Also, Elway only ever lost a game once in his career in which his defense held an opponent to 10 points or fewer. Meanwhile, Montana lost up to 4 games in that situation during his career even by playing fewer games. This helped him mostly avoid a below average performance in lower defensive points allowed brackets.
When it came to offensive help, Elway usually only had 1-2 players at best that were productive and pro bowl caliber during the first half of his career. During the 1980s, he did not have an all-pro level offensive teammate. Things changed when he got to play with Shannon Sharpe and Zimmerman before later playing with Terrell Davis, Ed McCaffrey, and Rod Smith. When analyzing Elway’s career in terms of record differentials, his ability to win relative to the average quarterback is impacted more by the offensive coaching than even the surrounding personnel.
Even with a very mediocre offensive situation, Elway was able to average 2 wins above average after his rookie season from 1984-1987 with Mike Shanahan being the offensive coordinator from 1985-1887 despite the underwhelming passing statistics. Once Shanahan left, Elway’s record differential plummeted to essentially average and even a game below average from 1988-1990 when Chan Gailey was the offensive coordinator. This was the case while still having a mediocre offensive situation. In the early 1990s with different offensive coordinators, Elway’s record differential only marginally improved to the point where he was only averaging a game above average for the most part despite having two elite players in tight end Shannon Sharpe and tackle Gary Zimmerman.
Things changed in the second year of Mike Shanahan’s head coaching tenure which was in 1996. From that season until the end of Elway’s career, he started winning more than 3.5 games above average. In addition to Shanahan’s presence, the offensive situation improved even more with the emergence of star players, especially all-pro level running back Terrell Davis, who even had an MVP. In summary, Elway is susceptible to changes in offensive coaching more so than in offensive talent. He can be fairly productive in producing wins above average even with mediocre talent on offense as long as Mike Shanahan is there in some capacity. Elway is at his very best when Shanahan’s system is there and then elite offensive talent is added on top of the situation.
Jim Kelly’s time when he was in the USFL is counted when calculating his career regular season record differential because he chose not to go to NFL. Those years are registered as having 0 record differentials but added when calculating Kelly’s career average. He did not want to go to the Bills because of the cold and because he didn’t trust that the team would build well around him. He shouldn’t get a pass by having those years dismissed. It essentially punishes other quarterbacks for going to organizations and risking having bad seasons on bad teams with it being counted in their career record differential.
For Kelly’s career, he’s had defensive support that ranged from mediocre (an average quarterback being a little under a game below .500) to pretty good. In 1988 and 1993, the defensive support for Kelly was great as the average quarterback would have won 5+ games over .500. During many of those solid to strong defensive support seasons in the late 1980s to mid-1990s, Kelly still had a lot of offensive help. He had multiple pro bowl/all-pro level offensive linemen as well as consistently elite running back Thurman Thomas and receiver Andre Reed. Despite the help on offense, Kelly was basically average in terms of record differential until 1990 and then the offense launched the K-Gun offense. He started producing very well to great record differential seasons for a three-year stretch, in 1990-1992. To Kelly’s credit, he was able to run the K-Gun offense effectively.
For the final few years, he was basically average to just barely a game above average outside of 1995. During those final four years, the offensive talent around him started to dwindle around him and the league was starting to catch up to the K-Gun. Outside 1995, Kelly was only ever good and able to win 2+ games above average in the regular season when he was running the K-Gun with excellent offensive talent at the same time.
Cunningham’s defensive support ranged from sub-mediocre to good. A lot of the seasons would have had an average quarterback winning between a game below .500 and a game above .500 with a few exceptions. Once Cunningham became a full-time starter, he oscillated between nearly winning a game above average and then winning around 2 games above average. The changes in scheme, the quality of his offensive players, and their health did not appear to influence how high or low his record differential was during his time in Philadelphia. When he became a full-time starter, his record differentials of 2 occurred mostly in his earlier seasons as a starter before gradually decreasing outside 1993. He soon became below average in wins in his last couple of seasons with the Eagles.
He had an outlier 1998 season in which he was great by winning over 5 games above average. He was in a great situation offensively as he had multiple all-pros and pro bowlers that season. The following year, his record differentials dropped significantly despite having the same personnel, with the difference being that his offensive coordinator left. It seems as though Cunningham’s dual threat style of play provided value in the regular season in terms of added wins, but that impact started to dwindle as the years went by in Philadelphia. He was only ever productive in 1998 as a veteran when he had a great offensive situation, but still needed a good offensive coordinator in Billick to be in the mix or else he wouldn’t be able to sustain it which was shown in 1999.
Warren Moon spent his first 6 professional football years in the CFL. When adding up his regular season career record differential, the first 6 years are accounted for by calculating the average, and those years each registered as a 0 record differential since he wasn’t in the NFL. It is counted for because those were professional years that could have been in the NFL if he chose to go there, albeit opportunities were likely limited due to racial barriers black quarterbacks faced in the late 1970s. In the NFL, Moon had a decent amount of bad defensive support since the average quarterback would have gone multiple games under .500 in those seasons. He had a few decent defensive support seasons and some excellent defensive support seasons in which the quarterback would have won multiple games above .500.
Moon only had positive record differential seasons when he had multiple star wide receivers and or at a star running back. If he had even one less productive player, even if the rest of the supporting cast was still pretty good, he ended up basically being average and even below average when to his record differentials. He had negative record differentials for his first few seasons in the NFL even as a veteran that had good players on offense. During his good seasons, he never peaked higher than barely over 3 games won above average. Most of his decent to good seasons were winning a little over a game above average and winning around 2 games above average a couple of times.
