This week’s Fifth Down post looks at the surprising 3-0 Cardinals. Did you know that Arizona has been an underdog in each game this season? Since 1978, Arizona is just the 7th team to start 3-0 despite being given points by Vegas each week:

• 2010 Kansas City Chiefs: The 2009 Chiefs were 4-12, and 2010 wasn’t expected to be much better. But despite being underdogs against San Diego, Cleveland and San Francisco, the Chiefs won all three games, en route to a 10-6 season and an unlikely division championship.
• 2007 Green Bay Packers: Surprised to see the Brett Favre Packers on here? Green Bay had gone just 8-8 the prior season and faced a brutal early schedule in ’07. The Packers were a 3-point underdog against Andy Reid and Donovan McNabb’s Philadelphia Eagles in the opener and 2.5-point underdogs against the eventual champion New York Giants in week two. In week three, San Diego — 14-2 the prior season — was a 5.5-point favorite at Lambeau Field. Green Bay would start 4-0 and finish the regular season 13-3, but the team’s hopes ended in overtime in the N.F.C. Championship Game against the Giants.
• 2004 Jacksonville Jaguars: Jacksonville had back-to-back-to-back crazy, last minute wins to start the season 3-0. In the season opener in Buffalo, Byron Leftwich threw the game-winning touchdown on 4th and goal from the 7 with no time left to Ernest Wilford, giving the Jaguars a 13-10 win. Jacksonville led Denver 7-6 in their home opener the next week, but the Broncos had the ball with 37 seconds left on the Jacksonville 23-yard line. Then Denver running back Quentin Griffin fumbled, Akin Ayodele recovered, and the Jaguars were 2-0. The theatrics continued the next week against Tennessee. Trailing 12-7 with 13 seconds remaining, Fred Taylor scored a one-yard touchdown to keep the streak alive. But the anemic offense eventually caught up to the Jaguars, who missed the playoffs after going just 6-7 the rest of the way.
• 1997 Tampa Bay Buccaneers: Tampa Bay drafted Warren Sapp and Derrick Brooks in 1995. Tony Dungy came in 1996, and Tampa finished 6-10. The Buccaneers drafted Ronde Barber in 1997, and the key cogs that formed one of the league’s most dominant defenses were then in place. Tampa upset San Francisco at home and then won at Detroit and Minnesota in week three; the Bucs would eventually go to 5-0, before finishing 10-6 and earning a playoff berth.
• 1996 Carolina Panthers: Dom Capers completed one of the great coaching jobs in NFL history, taking Carolina from an expansion team in 1995 to the N.F.C. Championship Game in 1996. Carolina beat Atlanta and New Orleans, but really caught the attention of the NFL when they defeated San Francisco 23-7 in week three. Behind an excellent defense and an efficient offense, the Panthers finished the season 12-4.
• 1992 Pittsburgh Steelers: Chuck Noll’s last season was 1991, when Pittsburgh stumbled to a 7-9 record. Expectations were not high for rookie head coach Bill Cowher’s team in ’92. As 12.5-point underdogs in Houston, the Steelers pulled off the upset 29-24, before handily defeating the Jets and Chargers in weeks two and three. Pittsburgh finished 11-5 and made the playoffs.

What can we make of the Cardinals’ surprising start despite being underdogs? Combining the three games, Arizona has been underdogs of 17 points so far this year. How does that compare to other 3-0 teams?

From 1990 to 2011, there were 111 teams that started the season 3-0. Only the ’92 Steelers were bigger underdogs at -18 points. The table below divides the 111 teams into four groups, based upon the total number of points they were given (or they gave) in their first three games. For example, 19 of the 3-0 teams ended up being given more points than they gave (i.e., were underdogs) in their first three weeks; on average, they were 2.4-point underdogs, and on average, they ended the year with 9.5 wins (which means they were an even .500 over their last 13 games). As you can see, there is a pretty clear relationship between expectations and ultimate results.

Spread            #Tms   Avgline SeaWins
Underdogs         19     +2.4      9.5
0-9.5 pt Favs     29     -1.6     10.2
10-19.5 pt Fav    37     -4.9     10.9
20+ point Favs    26     -7.9     11.7

You can read the full post here.