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Football Study Session: Offensive Line Basics

Tyler Smith

We've done a lot of work on different parts of Clemson's offense and defense in the past. We've looked at specific plays, overall schemes, and certain parts of technique. I wanted to get back the basics though by discussing offensive line terminology. Spend a little time with what gaps are and terms like playside, backside. It is hard to understand a zone blocking scheme if these terms can be met with a stare more appropriate for how we lost to USC again rather than one of understanding and enlightenment.

Gaps01_medium

So first lets talk gaps, probably the simplest thing to understand. Start with the center and the gaps on either side of him are called the 'A' gap. The 'B' gap is then between the guard and tackle on both sides, and the 'C' gap is on the outside of both tackles. If a TE is on the line, then there will also be a 'D' gap on the outside of the TE.

It is pretty simple to see why gaps are so important. On offense the goal is to plug them and prevent the defense from getting through as well as attacking them when running the ball. When a TE is on the line, you will often hear the term closed or strong used to describe that particular side.

Blocking_assignments_21_sankey_td_medium

The next term to talk about is splits. You have wide splits and tight splits, seen above. Again another simple concept, but something you aren't always going to think about or actively recognize. Tight splits come when the OL gets close together. It is referred to has hip-to-hip though that is more of an expression than a literal description. You are normally going to see tight splits used during a game. It is also the traditional split used for passing, it tries to prevent penetration up the middle and force the defense around the outside to give the QB more time to throw.

Wide splits are a bit rarer though they are very easy to recognize. Depending on the play and the offensive coordinator, wide splits vary in distances of 3-6 feet. Originally this split was extremely common for option teams. By going wide the man the QB needs to read is easily identified and they use a man blocking scheme which we'll get into at a later date. Now we see more and more air raid offenses using a wide split. BYU back in the 80's and 90's was when wide splits in the passing game became a thing if you will.

Finally we'll talk a bit about OL calls. We've spent a lot of time discussing calls at STS and who is responsible for missing a player and causing a sack. In most schemes, the first call comes from the center to identify the MIKE (linebacker directly in front of the center 4-5 yards away). After that in the running game the covered lineman will call any shade or techniques with the uncovered lineman responsible for double teams. In the passing game rather than double teams shift calls will be made. We'll cover shifts in another article.

The shades and techniques above are in reference to what the defense is doing. Essentially they OL is calling out what the defense is doing and how they are going to block. Depending on the situation the QB might do some direction.

Next time we'll cover some of the basics of the DL before moving onto some of finer details of OL and DL play.