Which players are actually protected?

Not much drama Saturday in the opening round of the NFL's wild-card weekend.

For the record, both home teams won — Houston over Cincinnati and Green Bay over Minnesota.

The most entertaining part of the day was following former professional wrestler, The Iron Sheik, and his analysis of the two NFL games on Twitter.

A sampling:

If you don't buy my autograph tonight at theironsheik.org you are worse than mark sanchez, tony romo and now joe webb.

Speaking of Twitter, I'm wrestling with how I can get fans to understand the difference between legal and illegal hits involving defenseless players.

All you need to do is follow me on Twitter to see how many misconceptions there are.

Who is considered defenseless?

There are only nine players, and that includes:

• The receiver of a kick
• The quarterback after a change of possession
• The kicker during a kick
• A runner on the ground
• A runner whose forward progress has been stopped
• A player who is being blind-side blocked
• A player who is being crack-back blocked

But the main focus is on the quarterback in the act of or just throwing a pass, and the receiver attempting to catch a pass. Anybody else is not defenseless. A runner, therefore, is not defenseless.

DIVISIONAL SCOREBOARD

• Ravens 38, Broncos 35 (2OT)
• 49ers 45, Packers 31
• Falcons 30, Seahawks 28
• Patriots 41, Texans 28

Is it considered legal to launch?

Yes. Launching on its own is not a foul. It's the type of contact that makes it a foul. If you lead with your helmet, it's a foul, period, no matter where you hit a defenseless player. Again, the key is the tackling player's helmet. Lower your head and you're in trouble. Keep your head up and you're legal.

Which part of the helmet makes a hit illegal?

The rules constantly refer to the top/crown or forehead/hairline portions of the helmet. The focus clearly is on the top of the helmet and the type of contact that occurs. Even when defining roughing the passer, the rule book states that the rule does not prohibit incidental contact by the mask or non-crown parts of the helmet in the course of a conventional tackle on a passer.

Two plays from the Cincinnati-Houston game clearly demonstrated the difference to me. Let's look at two plays:

NO. 1: NO FOUL

ASK MIKE

Our football refereeing guru is on Twitter and takes your questions during live events. See his latest tweets and his latest analysis.

The Play: Cincinnati had the ball, first-and-10 at the Houston 38-yard line with 10:38 left in the fourth quarter. Houston led 19-13.

The Situation: Cincinnati quarterback Andy Dalton attempted a 38-yard pass to A.J. Green that was broken up by Johnathan Joseph and Kareem Jackson. Jackson put a hit on Green right has he was about the catch the ball and knocked the ball loose. Many fans tweeted me to ask why a helmet-to-helmet hit was not called on Jackson.

My Take: To me, this was not a foul. The first element that you look at is whether the defensive player leads with his helmet. In this case, Jackson kept his head up and made initial contact with his arms and then his face mask to the upper chest of Green. The key is he did not lower his head, which is something the league has been preaching for the last few years.

Jackson also did not lead with his shoulder or forearm into the head or neck area of Green. It's a good example of seeing what you hit, which is what coaches are supposed to teach defensive players.

NO. 2: THE FOUL

The Situation: Houston had the ball, third-and-2 at the Texans' 36-yard line with 2:33 left in the game. Houston led 19-13.

ACCORDING TO JIM

This could be a season of destiny for the Harbaugh-led 49ers. See who's in the playoffs, and when they play.

The Play: Texans quarterback Matt Schaub completed a 6-yard pass to Garrett Graham and was hit helmet-to-helmet by Bengals linebacker Vontaze Burfict. A 15-yard unnecessary-roughness penalty was called and the Texans were awarded a first down.

My Take: This was the exact opposite of the previous play. Burfict approached Graham, lowered his head and hit him with the crown of his helmet flush in the face mask. This is the type of hit that causes concussions and neck injuries, and what the league is trying to eradicate. The risk factor is clear when comparing this hit to the play on Green above. If I were still in the league office, I would use these two plays at back-to-back comparisons as to what is legal and what is not. It all seems clear to me.

I guess there is a bright side to what transpired Saturday . . . We still have Sunday's games to look forward to.