There are two distinct labels for a "safety" in football: strong (SS) and free (FS).

Ed Reed (FS) and Troy Polamalu (SS) were two of the premier players in the NFL "in the safety position" during their careers. As far as I can tell, they line up in the same position on the field and seemingly do the same things. I hear a strong safety is more responsible for the run game and a free safety is more responsible for the pass game.

What is the difference between a strong safety and a free safety?

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    I think that this answer is great, but just in my general opinion, I think that the strong safety is more likely to have a man in coverage while a free safety is roaming 80% of the time. This can vary depending on scheme or formation (i.e. teams that play a lot of zone and prevent defense don't have anyone in man coverage), but in simple schemes, that is usually the case.
    – user962
    Commented Dec 10, 2012 at 18:03
  • @fleethefactory You are absolutely correct, in a simple scheme the strong safety would be playing man on a tight end or running back while the free safety would be in a deeper zone basically keeping the play entirely in front of him
    – Maniac
    Commented Dec 10, 2012 at 20:29
  • Strong safeties are better because they can blitz and play man.
    – user7697
    Commented Dec 14, 2014 at 16:25

2 Answers 2


The strong safety lines up on the strong side - whichever side of the center has the most lineman on it (typically the tight end is the extra guy). If both sides have an equal amount of lineman (maybe a tight end on both sides of the line) the strong safety will typically line up across from whichever tight end they want to shut down in the passing game or whichever side they believe the run is going to go to.

Strong safety refers to the fact that the safety in that position is playing on the strong side of the field. Just like a strongside linebacker, the strong side of the field in man coverage is the side of the field where there are more lineman and where a play is designed to be run. A typical indicator is where the tight end lines up.

In man coverage, the strong safety has the obligation of covering the tight end down the field AND coming up to provide run support. In a man formation, he will typically line up closer to the line of scrimmage so he can pick up the tight end quicker as the tight end runs by the strongside linebacker, who is the first line of defense on the strong side.

Like the strongside linebacker, the strong safety is normally a bigger safety who is fast enough to make up ground in the pass game, but who can take on tight ends and fullbacks to make a tackle on the running back in the running game. The strong safety has to be a big hitter, has to be tough, and has to be good at shedding blockers and taking the correct angle to get to the runner the quickest. He's often the safety that will blitz the quarterback on a third down as an overload on either side of the formation.

The free safety position is much different than the strong safety position. With strong safety, you really need a particular style of player who is rugged and rough. Free safety the player normally needs to be great at coverage and understanding the angles to get to the ball. It helps if he's taller and leaner and is a great jumper as well. He can't be afraid to make a big hit, but also must time his hit the right way to jar the ball loose and not get a penalty. He is the guy that makes the wide receivers scared to go over the middle.

He's also the guy tasked with locating the ball and meeting it at the point of attack, whether that point is an interception, deflection, or that big hit. He's tasked with "playing the field" and assisting the cornerbacks and he often plays zone when others around him are playing man. When he does play man defense, it's often because there may be a blitz package or a run style defense (like a 4-4) they are in. At that point, he has the duties of a corner in coming up more to pick up a wideout. The weakside linebacker will normally act as the strongside linebacker does with the tight end and drop with the WR for a few yards until the free safety picks him up.

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    Is the tight end indicative on where the SS lines up regardless of formation? How about 2-3 TE sets?
    – user527
    Commented Dec 10, 2012 at 15:26
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    edited. Explained that further. Obviously this could vary slightly based on gameplan, matchups etc. But as a general rule, yes
    – Maniac
    Commented Dec 10, 2012 at 15:33
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    Would it be safe to assume that FSs are speed/coverage guys and SSs are more all-around (need speed but hard hitting abilites as well)?
    – user527
    Commented Dec 10, 2012 at 15:44
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    As a general rule I would say yes but once again there are exceptions. For instance Ed Reed is considered a full safety and one of the best cover safetys in the league but he is also a big hitter. He is the one that makes wide receivers fear crossing the middle of the field and thats what makes him great. And although Troy polamalu also delivers big hits and covers well, he is more known for being a sure tackler and excellent run defender. Those two guys and a few select others would probably be versatile enough to play both positions depending on the situation
    – Maniac
    Commented Dec 10, 2012 at 15:55
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    A FS may be a better cover player against faster receivers, but may not match-up as well against larger ones (TE/FB/H Back).
    – JeffO
    Commented Dec 26, 2012 at 18:41

Generally, your right but it really depends on how the Defense was constructed. As the FS, they must have ball skills and coverage skills while having the ability to disguise their coverage. QB often look at FS to tip the defense's coverage, so FS must be smart enough to play the cat and mouse game with the QB's eyes. FS is the leader of the secondary (like MLB for LB). While both must be adequate against the run, SS are also called upon to cover the TE which means physicality is a must while FS will be covering mainly WRs or slot receivers. FS also must have the abilith to cover ALOT of ground (especially in cover 2 shell) and provide help so the corners can play to their strengths (i.e. ball Hawking corner vs coverage corner)

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    Welcome to SE.Sport. Can you please add any references on your reply?
    – Ale
    Commented May 2, 2016 at 5:49