I coach American football so I will try to help as I can...
The Tight End position is mainly one of a blocking nature. You're more/less a 2nd Tackle on the outside of the offensive line. More often than not, in a run heavy offense, your job is going to be blocking down on a Tackle, crack blocking a Line Backer or blocking out on a Defensive End.
Most of your pass routes will probably be "check down" routes, which means running a short hook route and sitting in the soft spots of a zone defense or running a 5 and in/out across the field and being the Quarter Back's "check down" option, or his last option to dump the ball off to in the event that his primary receivers (Split End and Flanker) are not open, or I guess if you are open and a play can be made to get you the ball.
Some plays are designed for the TE, too. A good offensive coordinator or a good QB will be able to read a defense and take advantage of any chinks in the armor, so to speak, which will usually mean (for the TE) taking advantage of the middle of the field being open in certain zone and man to man coverages.
In a pass heavy offense, the TE's role becomes much more involved. He will spend his time blocking on the line for the QB, sure, but he will spend just as much time (sometimes more depending on his talent and the defense) running routes and, again, taking advantage of the zone and man to man defenses.
As a TE you will have to know every play in the playbook. Split Ends and Flankers tend to have it easy on running plays but the TE will need to know (and be heavily involved in) both the running and passing game. The position of TE is more of a support role than one of a playmaker role like primary running backs and receivers. It's an unglorified and often thankless job, much like a lineman, so get used to that.
Feel free to ask any questions you have or PM me if you need to.
- Huges
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Don't make me go pop the trunk.