The Detroit Lions are a vertical passing team. Quite often, short passes act as a kind of extended handoff. The Philadelphia Eagles used to constantly do this with Brian Westbrook, and now Lesean McCoy. It stems from the fact that Philadelphia has a pass-blocking offensive line.
Contrary to what many commenters on sports articles believe, there are typically two pretty distinct ways to build an offensive line -- Pass-block first, or Power-Run first. It is very rare and would be quite difficult to find players that excel at both of these skills equally. The nature of the beast is that as an offense you have to choose your identity. The Lions are a passing team, and have a pass blocking line.
Essentially, the short throws force teams to roll coverage short/inside, allowing Detroit to take some long shots down the field. If they keep multiple guys up top to cover Calvin Johnson, then they are leaving Titus Young, Nate Burleson, Tony Scheffler, or Brandon Pettigrew with a favorable matchup. (and also whatever back is coming out of the backfield)
Oakland for years has run a straight up man coverage with lots of pressure on the opposing QB. Without Nmandi Asmogouha in the defensive backfield, I'm not so sure that was the best of ideas. The Raiders essentially manned up on the WR and then sold out run blitzed (essentially if not in fact by where they were positioning players) to bring the heat on the Lions. In essence, they wanted to force Matthew Stafford into making a long series of short throws to get down the field with players in his face. While they knew their secondary wouldn't really be able to cover Calvin Johnson downnfield, they tried to make sure Stafford didn't have time for any long plays to develop.
For the most part, it worked well for the Raiders. The Lions really had no running game, but still managed to put up two TD's up to midway through the 4th quarter. The pressure was getting there just enough to keep the Lions off balance. However, they misjudged a couple of factors that went against them on the last two drives.
The first problem with Oakland's strategy was that the Lions really don't care if they do have success on the ground as long as the passing game is clicking. This meant that often Kevin Smith was held in to block -- especially on the last two drives. While Jahvid Best is a more dynamic runner, Kevin Smith is the best blocking back on the roster. He excels at blitz pickup and keeping the QB clean when the opposing defense brings extra rushers. The Lions also have Brandon Pettigrew and Will Heller on the roster -- two more excellent blockers that you still have to account for if they break off for a short pass play.
The second miscalculation was the ability of Calvin Johnson to beat multiple guys in coverage. It really does take more than one person working together very well to keep CJ under wraps. Oakland just didn't have that.
When you put those together, you end up with Megatron having some huge plays on the Megadrive. Oakland sends sends extra rushers at extra blockers -- only the fact that Stafford is forced to sidearm the throw to get it down the field stops CJ from getting a TD on that throw. (its a good thing too -- it would have left too much time for the Raiders to get into FG range) So while the Raiders strategy allowed them to hold down the Lions for a while, they adjusted and were able to show that when this offense is clicking, they can knife down the field in a hurry and a half.
What Oakland learned is something teams should have been well aware of at this point: after now 4 times coming back form 13 or more down this season, the Lions can score so quickly that no lead is safe. As this team matures and becomes more consistent, it is just mind boggling to think they are just scratching the surface of what they can do.
Can you imagine if the Lions offense can come out in the first quarter like it has been in the 4th? And to keep it up over a whole game? Look at the feared offenses of the Saints and Packers -- in a year or two the Lions are set to be that good -- or possibly even better.
In the end, while Oakland tried it's best to contain the Lions all they really ended up doing was providing an abject lesson in how not to defend Calvin Johnson -- the number of which seem to grow longer each week.
These Lions can play against any team in the league, and have a good chance to beat them any given Sunday. So watch out Chargers -- you may have a lightning bolt but the Lions are playing electric right now too!