What is all this “op in [dex]…” stuff about?
Because a lot of the discussion around freestyle takes place over e-mail (since freestylers are spread out all over the world), an early member of the freestyle discussion list, Ben Job, came up with a notation for writing down tricks in e-mail. (It was actually for an assignment in a college course he was taking at the time.)
Here is Blur in Ben Job’s notation, as a point of reference for the rest of the tutorial:
clip > op in dex > op in dex > op toe
(1) Ben Job realized (and it wasn’t so obvious before, believe it or not) that moves basically start with one of two sets: either a toe or a clipper, so each move in his notation is “clip >” or “toe >” meaning “clipper set into” or “toe set into”; and moves basically end with one of two contacts (toe or clipper).
So in the case of Blur, the move usually starts with a set out of a clipper delay and ends with a toe.. Hence: “clip > … > … toe”.
(2) The “>” can be read as “into” or “followed by”, but is a special symbol because if you say “into” or “followed by” people aren’t sure if you mean there’s a contact in between or not. The “>” expressly means “without contacting the bag between the things on either side of the > symbol”. So when we use “>” we are never talking about “strings” of moves; only about “components” that go into the moves. Hence I tend to refer to each thing after a “>” but before the next “>” as a “component”.
(3) Ben further noticed that in a huge percentage of the moves (and all of the basic ones), you can easily describe a move in terms of the dexterities involved — i.e., whether a leg goes “in-out” (mirage-style) around/over the bag, or “out-in” (butterfly-style, reverse-mirage style). To avoid verbosity, these are shortened to just “in” for “in-out” and “out” for “out-in”. And the word “dexterity” is shortened to “dex”.
So in the case of Blur, the notation would give us “… in dex > … in dex …” to represent that there are two sequential in-out dexterities in the move.
For this tutorial, let’s ignore moves like “pogo” and “symposium” and other moves where plants and spins (gyrating, in-spinning, etc.) are significant. They *are* handled by the notation, but it’s best to understand the BASIC form of the notation before getting into that stuff, so I’ll leave it for another tutorial. (Some of that notation is also open to debate as to whether or not it covers every case.)
(4) The only other confusion might be “opposite” versus “same”. We decided that, to avoid having to write a move description twice, once for the left side and one for the right, and since people aren’t always in agreement about which side is which (don’t ask), everything would be “relative”. What I mean by “relative” is, when we say “opposite” (“op”), we mean “opposite to the leg/foot referred to just before the “>”, and when we say “same”, we mean “same as the leg/foot referred to just before the “>”.
So Blur set from either clipper would be:
clip > op in dex > op in dex > op toe
(The non-setting foot does the first in-out dexterity; the foot that didn’t do that dexterity then does another in-out dexterity; and you catch the bag on the toe of the foot that didn’t just do that final dexterity.)
(5) Why do we use “relative” meanings for “op” and “same”, and not use them to refer to “opposite of setting foot” or “same as setting foot”? The answer is, it really doesn’t make a big difference which way we use them, but we have to be consistent and agree to a particular meaning, and most people have accepted the convention in (4) above.
I personally think the one we’re using now is more sensible, and if you want to spent 1 more minute, read this reasoning. Otherwise, skip it and you’re done with the tutorial. Reasoning: if we write everything relative to the setting foot, it confuses the issue for variations on moves (such as “Paradox” or “gyrating”) where the components are exactly the same, but the set is different. So we (I?) prefer to be able to see the similarity in two moves by comparing their inner components without having to go and figure out which leg is which. If everything is relative (“opposite of or same as leg referred to in the previous component”) then things are generally simpler to cut and paste in e-mail. 🙂
- NOTE: Moves can start and end with other surfaces than toes and clippers, including insides (used like toes), dragons (used like clippers), and soles (used either way depending on whether they’re cross-body or not), but the description would otherwise be identical. So a move could be “inside > … > dragon” if it started with an inside set and ended in a dragon, for example. But the key is, regardless of which surface you use, all the stuff in the middle (after the set and before the pick-up) is the same. But let’s ignore those cases for the sake of understanding the basic notation. The terms at the beginning and end of the move description are really the least interesting (especially since most of us agree the set isn’t really part of the move, again not wanting to open a can of worms onto the great paradox debate :-)).
Entry last updated by Steve Goldberg on 2-Jan-1999.
Job’s Original Proposal
From: BJ <email@example.com> (now invalid) Subject: By the Way, Not the Name To: firstname.lastname@example.org Date: Tue, 31 Oct 1995 02:16:38 -0700 (MST)
Here’s some food for thought… Feedback is welcome, particularly in regard to the names in the list. Try the “complete” list…
This paper presents a notation for describing footbag tricks and representing the relationships that exist between them. Additionally, it presents the means for generating a comprehensive list of possible variations.
Break a trick down. You get a series of movements preceeded by a set and followed by a catch (or kick). The set and catch options are few and easily listable. The series of movements, though allowing of more variation, are similarly listable. Represented as a formula, this information provides us with the means to logically generate trick variations. As the precision of the formula increases, that is, as more of the finite number of basic movements are incorperated into the formula, we approach the specification of every trick possible. Consider the following:
(toe | clip) > [(same | op)(in | out)dexterity]* > (same | op)(toe | clip)
The notation is as follows: “Same” and “op” are always relative to the leg previously refered to. “In” and “out” mean “inside” and “outside”, respec- tively. “|” is equiv. to “choice” (“or”). “[ ]” means “enclosed dex is optional”. “>” is equiv. to “followed by”. “*” means the preceding term can occur/re-occur 0 or more times.
From this simple formula, most non-modified leg dexterities can be derived. Because of the structure of the formula, a “truth table” of moves can be gen- erated, leaving no move undiscovered (ex., see list).
- clip > op clip Clipper to Clipper
- toe > op in dex > op toe *clip > same in dex > op out dex > same toe Paradox Dbl Legover
- clip > op in dex > same in dex > op out dex > same toe Flurry
How far can we go? Only slight modifications are needed to account for other modifiers and their associated possibilities. For example, Pogo, Symposium, Spinning, ang Gyro moves can be formed by adding “(no plant while)” and “(forward | backward)spin”. The formula,
(toe | clip) > [(no plant while)] [(same | op)(in | out)dexterity | (for | back)spin]* > (same | op)(toe | clip)
describes variations such as:
clip > (no plant while) op in dex > op in dex > (no plant while) op in dex > op toe Pogo Paradox Symposium Blur
The set and catch options can be filled in with all the choices: inside, outside, knee, the unsual surfaces. What elements that may comprise a trick have yet to be accounted for? Just a few: stomping [“(both legs plant)”], blind, hop-over, carry (Wrap), duck, dive, jumping/flying, Swirl/Twirl cross- body dex, swing (Pendulum, Rake). Not many other types of primitive movements exist. Since the acceptable tricks are just combinations of these primitives; and since each primitive may be easily implemented within the formula; the the possibility of a master formula for all tricks becomes complete.
- Note: “same”, “op” and “no plant” are relative to the leg previously refered to.
- clip > op in dex > op out dex > op clip Ripwalk
- toe > same out dex > same out dex > op clip Double Over Down
- toe > op out dex > op out dex > same toe Eggbeater
- toe > (no plant while) > op in dex > op toe Symposium Mirage
- toe > (no plant while) > op in dex > op clip Symposium Whirl
- clip > same in dex > op in dex > op toe Pdx Blur
- clip > same out dex > same out dex > op clip Barfly
- clip > op in dex > same in dex > same toe Double Pickup
- clip > op in dex > (no plant while) op out dex > op clip Dada Curve
- clip > (back)spin > same in dex > op out dex > op clip Gyro Ripwalk