October 9, 2020 | 9:01am

Heading into Week 5 of the NFL season, we’ve witnessed many unusual happenings — not even counting the empty stadiums and everything else related to COVID-19.

We’ve seen huge scoring numbers highlighted by prolific offensive performances, and we’ve seen teams that look hapless and others that appear unstoppable. In a rare season on so many accounts, we have a pair of teams that are perfect at 4-0 SU and ATS and another pair that have yet to win outright or against the point spread.

How rare are these occurrences? Well, on the winning side, it’s not unusual. Since 1992, a total of 29 teams have gone 4-0 SU and ATS. For 2020, the Seattle Seahawks and Green Bay Packers are in that elite territory. On the opposite side, 24 teams over the past 28 seasons have begun the season on 0-4 SU and ATS skids, though only one since 2014. The New York Jets and Houston Texans add their names to that dubious list for 2020. How should we approach handicapping these teams in the immediate future and for the long term?

Past-performance trends of 4-0 SU and ATS teams

In terms of the fifth game for the 4-0 SU and ATS teams, most continue to roll, with a record of 17-3 SU and 12-7-1 ATS, including 9-0 SU and 6-3 ATS when favored by 4.5 points or more. At this point, Seattle is a touchdown favorite over the Minnesota Vikings this week, while Green Bay, on a bye in Week 5, figures to be an underdog when it next takes the field at Tampa Bay. Incidentally, all four undefeated teams that played as underdogs or favorites of two or fewer points since 2003 won their games outright and ATS.

Green Bay (38.0 points per game) and Seattle (35.5) join only seven other teams over the past 29 seasons that have gone 4-0 SU and ATS while scoring more than 35 points per game. The previous teams proved truly elite. All made the playoffs, three won the Super Bowl and two others were Super Bowl runners-up. They combined to go 75-28 SU and 48-52-3 ATS in their remaining games in those seasons, so it seems oddsmakers are quick to catch up.

Aaron Rodgers
Aaron RodgersGetty Images

What about 4-0 SU teams that weren’t 4-0 ATS?

Two other teams in 2020, Buffalo and Kansas City, are undefeated in the standings but not 4-0 ATS. Based on recent history, those teams also should expect a great deal of success. In fact, since ’09, teams fitting that description have gone 158-81 SU and 122-111-6 ATS in their remaining games. They were also 14-3 SU and 11-6 ATS in their fifth game. Six of the 17 teams also played in Super Bowls, with two winning titles.

Past-performance trends of 0-4 SU and ATS teams

The NFL has had only six 0-4 SU and ATS teams in the past 10 years, though we have two in 2020. Brace yourself, Jets fans, as all five teams that played as underdogs lost their next game while going 1-4 ATS. The only team that played as a favorite after its disastrous start, Pittsburgh in 2013, won.

Strangely, before the 2010 season, playing on 0-4 SU and ATS teams in their fifth game was a nearly foolproof strategy, as they had gone 15-3 ATS from 1992 to 2009.

None of the last 22 teams that started 0-4 SU and ATS wound up with a winning record, and similarly, none made the playoffs. The combined record of these 22 teams was 91-173 SU but 140-119-5 ATS (54.1 percent), so don’t write them off as potential point-spread plays down the line.

Houston is a truly unique case of a 0-4 SU and ATS team. Not only have the Texans played the toughest schedule in the league, they are ranked No. 2 in the NFL in my Effective Yards Per Play calculations. They are also the highest-scoring 0-4 SU and ATS team over the last 28 years, scoring 20 points per game. No similar team had scored more than 17.8 points per game. Perhaps the firing of coach Bill O’Brien was a bit premature.

Daniel Jones
Daniel JonesAP

What about 0-4 SU teams that weren’t 0-4 ATS?

Two teams in 2020 are winless in the standings but not 0-4 ATS, the New York Giants and Atlanta Falcons. Their playoff fates seem to have been sealed. It should be noted that Atlanta, at 26.5 points per game, is the second-highest-scoring 0-4 team in that time span and that the higher-scoring winless teams had achieved reasonable success the rest of the way. Combined, the teams that scored 20+ points per game in their 0-4 starts were 53-39-4 ATS (57.6 percent) in their remaining games, so consider the Falcons a live play the rest of the way.

Winless teams that are not 0-4 ATS have been a play-against group of late in their fifth game, going 9-18 SU and ATS.

What about 0-4 ATS but not winless outright?

This group includes the Dallas Cowboys, who are 0-4 ATS but 1-3 outright. This comes on the heels of lofty expectations. Unfortunately for Dallas fans, none of the last 15 teams that have started the season on an 0-4 ATS skid while winning at least one game outright have gone to the postseason. This trend dates to 2002. However, those teams have bounced back well in their fifth game, going 5-3 SU and 6-2 ATS in their last eight, an angle that could bode well Sunday for Dallas against the winless Giants.