*************** This is part one of the rec.sport.disc FAQ [Frequently Asked Questions list]. This file, and its companion file, part two, are posted bi-weekly to rec.sport.disc and news.answers. The posting is designed to answer questions which are commonly asked by new readers of the group, as well as to provide a reliable source of information for regular readers. FAQ Listing: ----------- FAQ.1: This FAQ contains the Questions and Answers for the sports of Ultimate, Disc Golf, and Miscellaneous disc-type questions. FAQ.2: This FAQ contains information which changes on a regular basis, such as UPA and WFDF contacts, Tournement schedules, phone numbers, and so on. Table of Contents: * Indicates new or vastly revised questions 1)* What is Ultimate? 2) What is Disc Golf? 3) Where can I get a copy of the Rules? 4) Am I eligible for Collegiate Disc? 5) How is the UPA Top 20 Computed? 6) What's a MAC, and how do I do it? 7)* How do discs fly? [ for the physicist ] 8)* Is there anyway to read rec.sport.disc if you don't have access to USENET? a) FAQ information and administrative swill b) Mailing Summary c) Technical Summary 1) What is Ultimate? ---------------- Ultimate is a fabulous, high-energy sport that can be enjoyed by people of all ages and disc-skills who don't mind a little running and a lot of fun. The description below applies to the outdoor version of the game. The indoor version, being on a smaller field, is somewhat modified (a slightly smaller field and fewer players) but mostly similar. Picture, if you will, a playing field (usually grass, but desperate teams will play on almost any surface) as follows: <- 25 yds -> <--------------- 70 yds --------------> <- 25 yds -> ^ +-----------+---------------------------------------+-----------+ | | | | | | | | | | | | | | | | | End | | End | 40 | | | | yds| Zone | | Zone | | | | | | | | | | | | | | | | | | | | | v +-----------+---------------------------------------+-----------+ On this playing field are two teams of seven players each. The object of the game is for a team to pass the disc from player to player, all the way up the field, and catch the disc in their end- zone, which scores a point. Players cannot run with the disc, but must plant a pivot foot (as in basketball) and throw the disc to a teammate. When holding the disc, a player gets ten seconds to throw it to a teammate (five or seven seconds indoors), which is counted off by the defender guarding the offensive player (known as "marking" the thrower.) If the disc isn't thrown in time, it's called a "stall" and the defense takes over. If the offensive team drops the disc, catches it out of bounds, or failes to complete a pass because a defender somehow blocks the pass, the other team picks up the disc where it lands and works to score in the other direction. Defenders gnerally play either a man-to-man or zone defense in their attempt to block a throw. The game is non-contact - it's a foul to hit the other player, or to hit the disc while it's being held. (Blocking the disc right after it's thrown, known as a "point-block", is a very hot play!) Nor can a defender be "picked" off the player being guarded. Any play carried out with the main intent to prevent another player from having a fair chance at catching the disc or making a defense is considered a foul; in other words, you have to "play the disc, not the person!" Probably the most important part of Ultimate is known as "The Spirit of the Game". This catch-phrase is used to describe the respect that every player in the game has for his fellow players. No referees are used in the game. Instead, each player does his best to make an honest call if necessary, and trust the calls of his fellow players, with the implicit assumption that nobody in Ultimate would try to cheat. This principle is what makes Ultimate special to so many people, and all Ultimate players try to keep the Spirit alive by maintaining this high level of trust, no matter how competitive the game gets. If people cannot resolve their differences, people usually say "back to the thrower", which allows play to continue on without forcing the issue one way or another. The best way to see how Ultimate is played is to go watch a local tournament. Ultimate players share a great comraderie, and LOVE to introduce new players to the sport. So come on out and watch! 2) What is Disc Golf? ----------------- [ Parts of this are paraphrased from the PDGA handbook. ] Disc golf is a recreational (and getting more into professional ranks) sport for everybody regardless of age, gender or ability. One thing is clear, throwing a flying disc with power and accuracy is a great sensation. The object of the game is to traverse a course from beginning to end in the fewest number of throws of the disc(more on what a 'golf' disc is later). Each consecutive throw is made from where the disc came to rest after the last throw. Score is determined by counting the number of throws made on each hole and then summing all holes. The winner is the player who completes the course in the fewest number of throws (OR whoever has the most fun!). A disc golf course consists of a series of holes laid out so that when a player completes one hole he proceeds to the next until all the holes have been completed. The player is provided with a 'tee' area from which to begin each hole and a 'target' such as a disc pole hole(made by the disc golf association). Disc golf courses are often laid out among wooded areas. They may also feature water and large elevation changes. Some courses have few trees and are considered very good. The natural obstacles on a disc golf course are an integral part of the game and should not be tampered with in anyway. Disc golf courses are usually 18 holes in length, however there are also 9 hole and 27 hole courses. The length of each hole also varies anywhere from 150 ft(although i haven't seen one lately) to over 425 feet per hole(average). The longest hole i have seen is 90 feet, the longest is over 1000 feet. Each hole usually has an amateur par(for those just starting out) and a pro par(for the more experienced disc golfer). Terms: Tee - this the area where the player starts each hole. Some courses have multiple tees for each hole. The material on the tee surface varies(concrete, asphalt, dirt, crushed stone, wood chips). In general, any flat non-slippery surface is good. Target - The target is where the disc must land in in order to complete the hole. The target is usually a 'pole hole' which is specially made to catch the golf disc. Courses that do not use pole holes(or pole hole like targets) are usually known as object courses. A typical 'object target' is a tree trunk, 4x4 or pipe. Golf disc - a 'golf disc' is a flying disc made especially for the sport of disc golf(although some players use whamo type 'frisbees'). Golf discs vary in weight and size. They are usually harder and denser than whamo type frisbees. Special models exist for driving, putting and 'up shots'(not as far as a drive, but more than a putt) much like different clubs exist(drivers,irons,putter) in ball golf. However, players are not required to use a 'driver' as a driver or a 'putter' as a putter. I have often seen players throw a putter as their first shot from the tee. A golf disc generally costs anywhere from $5-7 (US), maybe more or less depending on how many you buy. A professional PDGA tour exists. I have been told that over 100,000 people currently play disc golf. The PDGA currently has about 5000-7000 active members (some play on a professional level for money and some play on a amateur level (non cash prizes)). The top money winner last year won over $16,000 (US). 3) Where can I get a copy of the Rules? ----------------------------------- A anonymous FTP site for the rec.sport.disc archives is being set up. When this has been created, people will be able to get copies of the UPA, WFDF, and PDGA rules via anonymous FTP or mail services. For now, call or write the respective organization listed in FAQ.2. 4) Am I eligible for Collegiate Ultimate under the UPA? --------------------------------------------------- [ I would appreciate it if this space could be filled with a concise summary of the latest UPA rules modifications...I'd love to know exactly how things have been changed. ] 5) How is the UPA Top 20 List Computed? ----------------------------------- The UPA Top 20 is calculated by Eric Simon (UPA Mid-Atlantic Coordinator) and distrbuted weekly. However, the Top 20 isn't accurate unless college tournaments call in their scores! So, please, all college teams and tournament directors should send in their scores to Eric or the UPA (see FAQ.2 for a contact list.) The most basic explanation of the Top 20 rating system is this: for each game a team plays, the team gets rating points. These rating points are then averaged. The next level of complexity is how to compute the points for a given game, and how to avereage them. The points for a given game is given by this formula: pts = opp_rate + (400 / x) (1) where opp_rate is the rating of the opponent, and x is a factor that depends upon the score. The formula for x is: x = max(.66,(2.5*(losing score/winning score)^2)) (2) Rather than explain it, let me give an example. Suppose team A beats team B 15-11. According to the formula, take the fraction 11/15, square it, and multiply by 2.5. This gives us 1.34. Suppose, further, that team B has a rating of 1000. According to formula (1), we simply compute 1000 + 400/1.34 and get 1298. The "max" that's used for formula (2) makes it so that the smallest that x can equal is .66, which means that the best (or worst) a team can do in a specific game is to perform at 600 points better (or worse) than their opponent. (A score of 13-5 will get you 600 points). So, suppose team A has played in 4 games, and each individual game rating is 1298, 913, 1410, and 1103. Well, we simply average them together, and team A has a rating of (1298+913+1410+1103)/4 which is 1181. But, actually, the averaging isn't quite that simple, either. We actually take a weighted average. In the above example, each game had a weight of 1, in actuality, the weight depends upon how recently the game was played. This formula is: wt = min(1,1/(((today-gamedate+4)/7)^.4)) (3) Suppose games were played on four consecutive Saturdays. Since the ratings are done on Mondays, this would mean that the games were played 2, 9, 16, and 23 days ago. Well, by formula (3), any game played within 3 days of the rating gets a weight of 1. Games played the week before, or 9 days ago, get a weight of 1/((9/7)^.4) which is about .9. The games 16 days ago are weighted at about .72, etc. This is called a decay function, and, basically, it means that the more recent the game is, the more heavily it is weighted. Finally, whatever the weight it, it is doubled for games at Regionals, and tripled for games at Nationals. After all, teams are usually at full strength during those tourneys, and the games are more important. Finally, it is hoped that the winner of Nationals will come out as number one in the rankings. Luckily this has always happenned, although one year a team that lost in the semifinals almost finished first. But that's not all! Suppose the ratings of the teams you play change. An underated team you lost to in the first round ends up winning the tournament. Should your rating reflect that teams' victories, in other words trying to take into account that the other team was a really good team. Of course it should. Suppose your team's rating went up during the course of the tourney, too; shouldn't other teams, in turn, get the benefit of that? This is done in an interative process. On Monday, every team gets re-rated. That is, we recompute every individual game rating, based on the previous week's ratings, and the new date. Then, each team gets a new rating for the current week. Then, we re-rate every team again, using this week's ratings, to get a new set of ratings. We do this 20 times (this is why a computer is indispensable). Eventually (usually after only about 8 interations) the ratings reach some sort of equilibrium. It's kind of a neat process to watch. If some team does really well, and the rating goes up 250 points, then, on the second iteration, all teams that have played the first team goes up by a smaller amount, and on the third iteration, all the teams that have played the teams that played the first team will go up by a small amount, and so on. The biggest problem with the system is that in some areas of the country not everyone is calling in scores. Let me give a classic example of how an entire region can be adversely effected by this. Suppose the best team in Region X always calls in their games (and, in fact, more winners than losers call games in). So, suppose this team "State U." calls in 13 games of theirs, all victories. None of the other teams had called in any scores. This team beat, say, team B in the finals of two other tournaments. Obviously, team B must've been pretty good to make it to the finals, but to the computer, team B was simply 0-2. In fact, to the computer, it looked like the 13-0 team was playing a really wimpy schedule because every team that had played was winless! So what happens? State U doesn't get a very high ranking. Now, weeks later, the other scores are called in. It's too late, State U is already ranked lower than they should be, and all these other schools are, correctly, ranked lower than State U is. So, the whole region gets ranked lower than they should be. 6) What's a MAC, and how do I do it? -------------------------------- A MAC, also known as a "mack", actually stands for Midflight Attitude Correction. In the sport of Ultimate, it usually happens by mistake, but here's how to do it on purpose. To MAC a disc effectively, one needs to be aware of the direction of spin the disc has. The two possibilities are clockwise (originating from a standard backhand throw from a right-handed player) and counterclockwise (a sidearm throw from a right-handed player). The best throws to MAC are hard with lots of Zs (spin). The technique is to allow the disc to be throw at you very hard, allow the disc to pass you, the MACer, on one side of your body or another, and just as the disc is perpendicular to the throw line, touch the side of the disc very briefly. If the throw is clockwise, allow the disc to pass your right side (as you are looking at the thrower) and tap the top of the disc's platter, near the outside of the disc at the point closests to you. The disc will then take a MAC, climbing upward. If the clockwise throw passes on your left, that tap will send it straight into the ground. Switch everything around for a counterclockwise throw. Disc passes you on the left, tap the side of the disc, it takes a MAC and climbs up. Disc passes on your right, tap it on the side, the disc dives down into the ground. There are some neat variations of the MAC, like the foot MAC, which takes some extra practice. Hitting the disc on the outside edge from the thrower is also harder. If you want to see one of the best MACers alive, watch Dan (Stork) Roddick sometime. He is amazing! (he is also the Sports Director for Wham-O). And no place is better to MAC than on a California beach somewhere. 7) How do discs fly? How can I find out more? ------------------------------------------ This is a listing of articles and research done by various people around the world on how discs fly. Harrison Ka., "Flippin Frisbee", New Scientist, 1990 Aug 11, v127 n1729:67-67. Johnson, Stancil E.D., "Frisbee: A practitioner's manual and definitive treatise", New York: Workman Publishing Company, 1975, ISBN: 0-911104-53-4. Katz, Paul, "The free flight of a rotating disc", Israel Journal of Technology, vol. 6, nos. 1--2, pp. 150--155. Nakamura Y, Fukamachi, "Visualization of the Flow Past a Frisbee", Fluid Dynamics Research, 1991 Jan, v7 n1:31-35. Schuurmans, Mac'e, "Flight of the Frisbee", New Scientist, 1990 Jul 28, v127 n1727:37-40. Schuurmans, Mac'e, "Frisbee: History and aerodynamics", Basel, Switzerland, February 1985 (in German, 51 pages). Simon, Craig, "Frisbee: Beyond catch and throw", 1982 (65 pages). Address: Box 1502, Santa Cruz, CA 95061. Some work has been done on converting discs into interesting weapons, by using the disc to launch either a flare or a hand grenade; these are discussed in some of the above messages. Apparently, the patent applications from Wham-O in the late 1950's are interesting reading material. See the patent section of any well-stocked university library for references in this area. frevi@athena.mit.edu did work as an undergrad (MIT) involving the visualization of flow around a rotating frisbee using dry ice vapor as the tracer aerosol and stroboscopic and conventional photography. In particular, a number of photos were taken of vapor flowing around a disc mounted on a motor in various orientations, the trajectory of a frisbee throw through a sort-of stationary flow field stopped stroboscopically, and various multiple exposures of throw/release motions. The results of the flow studies seemed to indicate that a rotating frisbee induces lift independent of a trajectory vector; i.e. the disc doesn't have to be going someplace to generate lift, just spinning. 8) Reading rec.sport.disc without USENET access -------------------------------------------- Currently, there's a mailing list called "ultimate-list" which people can subscribe to to read Ultimate oriented mail. It works as follows: To subscribe or unsubscribe, send mail to ultimate-request@doe.carleton.ca indicating your wish. Put something like "subscribe" or "unsubscribe" in the subject, which makes it easier on the host of the netgroup. The mailing-list sends a copy of everything sent to "ultimate-list" to everyone who is subscribed...in effect, a giant, unmoderated broadcast service, so spare some thought about what you send, because once you send it, EVERYBODY will get a copy.... If you have problems, send mail to owner-ultimate-list@doe.carleton.edu and the administrator will try to help you out. Big thanks to Jon Berlinger, manager of the list. a) FAQ information and administrative swill ---------------------------------------- This FAQ is maintained as a public service by David Birnbaum. Suggestions, requests, additional material, word of encouragement and constructive criticism are encouraged! Please send electronic mail containing all this and more to: davidb@is.morgan.com I encourage members of the electronic world to assist me in keeping this up to date. This FAQ is not directly affiliated with the UPA or any other organization at this time, nor is any guarantee as to the accuracy of this information implied or expressed. But I hope it's right.... b) Mailing Summary --------------- Any mail regarding this FAQ should be sent to: davidb@is.morgan.com ...or... ...uunet!is2!davidb depending on what your mailer speaks. I may be contacted via traditional means by calling: (212) 703-2360 after 5:00 PM. Leave a message if I do not answer. c) Technical Summary ----------------- This FAQ is maintained in a ASCII-text format in RCS. I use a SPARCstation IPC, running Emacs 18.57 to edit the document. The file is not yet availible via FTP, but I will mail copies to any email address if one is requested. For Technocrats only: $Author: davidb $ $Date: 1992/03/12 22:23:42 $ $Revision: 1.15 $ Forcing new posting of FAQ.1.