You do not want it to be too tight. A good rule thumb is that if you were standing arm's length from the fence and fell back into the fence, it would bounce you back to your feet. So in other words, it wouldn't catch you like a glove, but also wouldn't be like hittling a wall. It should spring you back to your feet. Just remember, your deer will be running full speed into this fence on a number of occasions so make it as safe as you can for them.