A lot of tournament systems use what is known as the Swiss-pairings system.
tournament format which features a set number of rounds of competition, but considerably fewer than in a round-robin tournament. In a Swiss tournament, each competitor (team or individual) does not play every other. Competitors meet one-to-one in each round and are paired using a set of rules designed to ensure that each competitor plays opponents with a similar running score, but not the same opponent more than once. The winner is the competitor with the highest aggregate points earned in all rounds. All competitors play in each round unless there is an odd number of players.A lot of games use this system for their events; A Swiss-system tournament is a non-eliminating
- Trading Card Games
- War games
The Swiss System
Once you get more than 4 players, it is usually unfeasible to have everyone face everybody else in the event. Time is always a factor in tournaments, both for Organiser logistics and Player endurance. So this system was created for a Chess tournament held in Zurich in 1895, which is where its name comes from. It even has a provision for having a Single Elimination mini-event afterwards to cement a winner.
It also ensures that during the rounds, no player faces the same opponent more than once. Even if they end up matching your record later in the event. The exception is if a top cut is done after the final round. You can totally face someone during the single elimination that you've already faced during the regular rounds.
How Many Rounds?
The number of rounds that an event should have depends on the event attendance. It uses the Binary Logarithm to determine this. Without getting heavy on the math, it actually gives a perfect number of rounds so that if you reach the maximum number of players for the round limit, only one player will be undefeated at the end of the event.
As you can see from the table above, up to 8 players gives you 3 rounds. 9-16 gives you 4 rounds, and so on. Essentially, an extra round allows for double the maximum players of the previous amount. If you play fewer rounds than recommended, then more than one player is likely to end up with an undefeated record. If you play more rounds than recommended, then you can not only end up with no players undefeated, but the pairings start going weird.
For the first round, everyone comes into the event fresh (events with a seeding system are an exception). Nobody has a win/loss record at this stage. So the way you pair the first round is by randomising the players into pairs, and that's their opponent. Then the first round is played.
Some events will look at the list of players and try and avoid pairing people from the same playgroup against each other if possible. This is to allow them to face new opponents, as nothing sucks more than travelling a few hours to an event, only to play the same guy you play at home in the first round. Most events won't do this though.
Round Two Onwards
From the second round, you are paired based on your win/loss record. That is, you should be playing against someone who has won as many rounds this event as you have. That is, round two, it pairs all the people that won round one against each other, and all the people that lost round one against each other. And this repeats as the rounds progress.
In round four, the players with three wins are paired, the players with two wins, the players with one win and the players with none. So your opponent should be having a similar day to you. Theoretically, they should also be close to you in skill level. This stops someone who is currently undefeated having an "easy" match against someone who has yet to win a game due to inexperience/poor deck choice/ unlucky day.
Within your win/loss bracket, you will usually be paired based on Tiebreakers. These are a system that differentiates players with the same record. You will be matched with someone whose tiebreakers are closest to yours, where possible. The only time you won't is where that would cause you to face someone for a second time.
They can also cause you to be paired up/down. If there isn't the maximum number of players, then there won't be an even number of people within each bracket so the person with the strongest tiebreaker in one bracket will be paired up into the next bracket against the person there with the weakest tiebreaker, again without repeating a pairing.
Different games systems will have different tiebreakers, dependent on the system. Magic the Gathering uses the average of your opponents win/loss records. Warhammer 40K uses the points scored in the game. Some smaller events will simply determine randomly who is at the top of each bracket.
If your round ends in a draw, this alters things slightly. As a draw is better than a loss but worse than a win, it alters your win/loss record. Most games cope with this by assigning a points value to each result, typically 3 points for a win, 1 for a draw and 0 for a loss. For example, end of round three somebody with three wins will have 9 points, somebody with one win will have 3 points and somebody with two wins and a draw will have 7 points.
These are called match points and determine what bracket you are in for pairing purposes. Everyone with the same number of match points is in the same bracket.
Draws usually happen because matches are timed. Either the players didn't finish with a victor determined or they didn't even have time to reach a conclusion. I want to talk about this more in a future post, as it heavily factors into the issue of Slow Play.
At the end of the recommended number of rounds, one player should be undefeated. If you are stopping here, they are the winner. They will have the most match points as well, to make it easier to spot at a glance. If due to factors such as time constraints, you've run fewer rounds then the winner is the player with the highest match points and the strongest tiebreaker.
The exception to this is if the event has a single elimination cut.
If the event is having a cut, then it will usually be announced at the start of the event. Sometimes this is determined by attendance, other times it's fixed by the standard of the event. At the end of the final round, the players that progress to the top cut is decided by their standings. Players are ranked by match points and then by tiebreakers to let you know who came first, second, etc.
Those players will then go on to play a number of knockout rounds until there is one player left undefeated. Top 4 is two rounds, top 8 is three rounds and top 16 is four rounds. If you lose a round at this stage, you are out of the event.
The final standings are also used to determine prizes.
Typically, my regular monthly events are small events. I run 3-4 rounds dependent on either attendance or game system. Warhammer 40K requires a long time for each round, so I limit the events to 3 rounds even though the attendance normally calls for 4. I pair my events using the Swiss system and use whichever tiebreaker is appropriate for the game. Some games even have their own software available, which makes a lot of the work easier.
For larger events, such as Store Championships, I also do a top cut. This depends on attendance but is normally factored into the event timing. This can often lead to someone being knocked out by a player that they beat in the regular rounds, often referred to as the "Swiss Curse". These tournaments are rarer though.
By having everything use a similar system, it makes it easier for players to understand what is going on during the tournament. Also, if there is a top cut, they can see their progress and how many more wins they need to ensure they make it.
That was a bit drier than normal, but its a dry topic. Hopefully, I've made sense and tournament structure is now easier to understand. Post any questions in the comments