In German football vocabulary, there exists a so called Abwehrsichel during defensive play. The meaning can best be seen at this youtube video at the 09 second mark:
http://www.youtube.com/watch?v=P_pFKGDEgUc
How I can translate this term into English. Could I translate it into "defense sickle"? It doesn't sound right to me.
I think Rupe is right in that there is no current, specific term for this in English football. However, the most natural phrase would be a defensive arc.
The sickle is too associated with agriculture and communism in British English to be merely used as a metaphor describing a shape. A defensive sickle is most likely to be wielded by an angry farmer. However, we have arcs everywhere: of prosperity, plot, history, underachievement, extremism, and so on.
The video name is "Abwehrkette", so this would translate into something like "defense link/chain", wouldn't it? It certainly looks like a chain more than a sickle. But if there exists a move/positioning pattern in the defense that looks like a sickle, I don't see a problem translating it "defense sickle", or simply "sickle" when it's clear we are talking about defense, not offense.
EDIT: Sorry, I misunderstood that "Abwehrsichel" is a separate move in the video, and not the whole move pattern. There is also "Abwherdreieck", so we talk about the defense positioning types. I guess you can say that the defense chain goes back, than forms a triangle, than forms a sickle, without repeating "defense" all the time.
From the video it looks to me like the "sickle" is when one end of the defensive line moves forward to meet the winger, creating a curve in the line.
In current English football parlance (in the UK, at least), I don't believe there is a specific term for that defensive shape. We would probably just refer to it as one of the full-backs "breaking the defensive line" to "close down" the winger, but that in itself doesn't convey the concept of the curve induced in the line when the neighbouring defender also steps forward.
The terms "Abwehrdreieck" and "Abwehrsichel" are used in the 4-4-2 system in which the defenders move as a unit and defend zones and not mark opposing players. When the opponents attack down the center, the closest midfielder or central defender moves toward the attacker and applies pressure while the two adjoining midfielders or defenders close the gap behind him establishing a defensive triangle the purpose of which is to create a sort of "no passing" zone. If the opponent has not penetrated the four midfielders the midfielders and the defenders form that defensive triangle. The distance between individual players and the two lines is about 10 yards. If the attackers have by-passed the midfielders, the defenders will form that defensive triangle and the midfielders will apply pressure from the other side so as to double the attacker with the ball. The term "Abwehrsichel" comes into play when the attackers and the ball are coming down the side. The midfielders and defenders now shift in the direction of the ball and they will do so not in a straight line but a line that looks like a sickle or crescent. In zonal defending defenders concentrate on the ball. They defend as a unit and they try to make sure that the attackers do not have the space which would enable them to create goal scoring chances either by passing or dribbling. Yes, there is a little bit more to it than I tried to explain but perhaps now some of the readers might have a better understanding of the terms defensive triangle and defensive sickle or crescent. If you watch the US National Women's team, you might be able to understand what I am talking about. Yes, the men's team uses more or less the same system, it is easier to visualize, however, when the women play because of the fact that the women's game is much slower.
