Saturday, May 9, 2009

Rating System for Turnabout

If something is popular, it is good to determine how proficient people are at it. This is the reasoning behind developing a rating system, so that there is a record of who is doing well at any given moment.

When it comes to Turnabout's rating system, it does not work well with an ELO-based rating that rises and falls based on match wins. Unlike standard Magic: the Gathering events, the match scoring system awards points based not just on the match win, but on the degree of that win. A person can win one match 30-0, lose the next one 12-18, but those 42 Victory points will still be more than the person who wins two matches 20-10. Given the nature of the event, it makes sense, for the first player has likely won 3 games out of 4, whereas the second player is likely to have only won two. The match win is often less important than earning enough Victory Points to secure a particular position.

This dynamic forces the rating system to acknowledge two separate factors: the number of matches won and the final placement of the players. To deal with these factors, each is given an individual rating, and these factors are multiplied together to determine the overall award for the event.

Match Wins
The number of matches won is easy enough to determine. For the purposes of this rating system, it is often beneficial to keep players involved in the event as long as possible. So toward that end, the system rewards players who play all scheduled rounds as having won an extra match. Thus a person who goes 1-3 in a four-round event would be counted as having two match wins; if the event were five rounds and the person dropped before the fifth round, only one match win would be recorded. Draws are counted as half a match win.

As has been mentioned before, Turnabout does not normally use any of the elimination formats, but for those, playing all scheduled rounds equates to playing until eliminated. Those who are eliminated naturally receive the bonus match win, while those who drop before being eliminated do not.

Final Position
This rating is determined based on a formula that guarantees that each match win will be worth at least one point, and that those who finish well will receive a better multiplier than those who do not. It is recommended that no event have fewer than four players, and these values will assume that there are at least four.

Number of Players

Multiplier for First Place

Position of Player

Modifier to Multiplier





















Each doubling


Each doubling

Additional -1


So a person finishing 5th in an event with 16 players would get 3 points per match win (6 for 16 players, minus 3 for 5th place), as would a person finishing 64th in an event with 100 players (9 for 100 players, minus 6 for 64th place).

Tuesday, April 28, 2009

Chess clocks in Turnabout (with lessons that can be applied to Magic universally)

Of all the ideas that have the potential to cause controversy, this one seems to strike the most nerves. I have always been willing to conduct Magic: the Gathering matches by chess clock, and have never had any of the problems that are claimed to be associated with such use. However, it seems appropriate to address these concerns, and my experience with them, before going into the details of how to go about implementing chess clocks for Turnabout.

Too much priority passing
Whenever I have presented the idea, someone thinks that it is clever to point out that, under the most strict interpretations of the Magic Comprehensive Rules, there are numerous priority passes that take place, even on a basic turn where a person might simply play a land and do nothing else. This fact supposedly renders the idea of a chess clock meaningless.

The argument itself would only work if several factors were true that simply are neither true nor relevant. The first assumption is that I am talking about having people "send the clock" whenever a person would gain priority. No one does that now, so to think that it will happen just because there is a clock present is silly.

The second assumption is actually a challenge to my first response. It is that people will choose to waste time off of the other player's clock by insisting on every priority pass. The way such an event would happen is if a third assumption were true, namely that the clock in question is a simple chess clock with no frills.

The answer to both of these lies in realizing exactly what is being proposed. Most advanced clocks today have one or both of the following options: Bronstein timing, or delay timing. Bronstein timing allows for a "refund" of time spent, up to a certain limit chosen by the event organizer. Delay timing creates a timer that counts down between ending one person's time and beginning the next person's time. In both cases, the phenomenon of deliberately striking the clock to pass priority just to burn time off the opponent's clock fails because the opponent can simply pass it back within the time limit and not lose anything.

In addition, the arguments can be made just as strongly against the current shared time model, if not moreso. If someone actually tried to enforce every pass of priority during every turn, it is likely that a judge would issue a slow play warning. In a normal match, that is clearly taking away from the shared match time; in the clock situation, if any time is being wasted, it is the person's own time, and as such, I have no objection to people being idiots on their own time.

The clock shouldn't influence the game
Another argument against chess clocks is that they shouldn't influence how the game is played. A game where each side only has a certain amount of time to play will remove certain deck strategies from the environment unfairly.

If the goal is to allow all strategies to be playable, the match should be untimed. If there is to be any sort of time limit on the match, it will, by definition, harm some strategies over others. In such a case, the only question is one of whether to divide the match time evenly through chess clock technology or let each match divide the time based on what happens during the match.

DCI would never sanction such an event
Regardless of what the DCI would sanction, this is currently an unsanctioned format (except as Casual Non-Rated Constructed). If it's already unsanctioned, what harm is there in adding another element?

So now that these are out of the way, let's go about dealing with the implementation:

Length of Games
It is recommended that each player have 10 minutes and that the Bronstein or delay time be 3 seconds. The clock should measure game time, not match time. This gives 40 minutes of play time, plus 8 minutes of prep time (5 in the first game, 3 in the second). Together with the various time that will add due to the refunded or delay time clocks, this will put the projected end of the match at about the same time as normal.

For Bronstein clocks, the 3 seconds need to be set as the refund time, and also added onto each person's base time (so each player's time should be set to 10:03). For delay timers, this is not necessary; give each player 10:00 and set the delay timer for 3 seconds.

Player shortcuts and communication
There are already a number of shortcuts that players use to get through games without doing every priority pass. These are fine and should be encouraged. If a person wants to do something on another person's turn, he should ask for the clock.

Resolution of spells and abilities
The only question that remains over and above the basic is whose clock should run while resolving spells or abilities. The answer is that the person who controls the affected object should resolve things on his time. If objects controlled by both players are affected at once, the player controlling the spell or ability resolving should have the clock running for whatever time is needed to resolve his or her affected objects; then if the opponent still has things to resolve, the clock should pass to resolve them.

Sunday, April 26, 2009

What is Turnabout?

Date of last update: March 29, 2013

Turnabout is a way of playing Magic: the Gathering using constructed decks that I developed and ran at GenCon from 1996 to 2002. It is unique among constructed formats in that the classic "four-of" rule (whereby no deck may contain more than four of any card that is not a basic land) is waived. This does not break the format, because half of the match is played against the deck you bring.

Deck Construction Rules
  1. Decks must consist of 60 or more cards. No sideboards are used.
  2. You may have as many copies of any non-banned card as you wish.
  3. The banned list consists of:
  • Ante cards
  • Cards that fetch other cards from outside the game (Examples: Ring of Ma'Ruf, Research/Development, and the Wishes)
As usual, cards that would not normally be tournament legal (such as silver- and gold-bordered cards and counterfeit cards) are not permitted.

Match Rules
  1. A match consists of two games. It is recommended that these matches be untimed if possible. If that is not possible, the next best option is to use a chess clock with either delay timing or Bronstein timing and give each player 10 minutes base time with a three-second delay. (This option will be discussed in another article.) If that is not possible, divide the base match time in half for each game, and invoke the Judge Armageddon Clock at the end of the turn in which game time expires. Play continues until the game is over. The judge may set the speed at which the Judge Armageddon Clock runs based on his or her assessment of the state of the game.
  2. For the first game of the match, players play with their opponent's deck against their own deck. When handing the deck to the opponent, the player states which of the scoring options (Dominaria, Phyrexia, Tolaria, or other) this deck will use in the event it loses a game. The opponent is allowed to look through the deck to see what it does. As a result, the pre-game preparation period for the first game is extended to five minutes.
  3. For the second game of the match, players play their own deck. As they presumably know what their own deck does, there is no extension of the pre-game preparation period for the second game. The person who played first in the first game plays second in the second game, and vice versa. (This necessarily means that the same deck starts both games.)

Judge Armageddon Clock

Judge Armageddon Clock
Emblem (Nothing can stop an emblem's effects from taking place.)
Judge Armageddon Clock may only be played by a judge.

When Judge Armageddon Clock enters the command zone, the judge chooses a number.

At the beginning of each upkeep, put the chosen number of doom counters on Judge Armageddon Clock. Then invoke doom. (Each team chooses one — each other team loses life equal to the number of doom counters; or each other team gains poison counters equal to half the number of doom counters, rounded up; or each opponent exiles cards from the top of their libraries equal to twice the number of doom counters.)
Scoring Rules
  1. This format does not use the standard DCI game and match point scoring system. Instead, the two games of each match can give a certain number of match points that only apply to that match. The player who has the most match points after two games wins the match. Each match awards a total of 30 Victory points, and the difference between the players' match point scores determines the division of those Victory Points between them.
  2. When registering for the tournament, players choose on of the available scoring options. When a player's deck loses (regardless of who is playing it), the winner gains match points based on the scoring option chosen. Currently, three scoring options are recognized; the Tournament Organizer and/or Head Judge may allow others. In all cases, the minimum match point value for a win is 10; the maximum is 30 (adjust values outside that range to the closest allowed value).
    • Dominaria: This is the default scoring option. When a Dominaria deck loses, the winner gains match points equal to 10 plus his or her current life total.
    • Tolaria: This option is commonly used by "mill" decks that try to run the opponent out of cards. When a Tolaria deck loses, the winner gets match points equal to 10 plus half the number of cards remaining in his or her library (rounded up).
    • Phyrexia: This option is often used by decks that inflict poison counters. When a Phyrexia deck loses, the winner gets match points equal to 30 minus twice the number of poison counters the winner has.
  3. Pairing is usually done using a Swiss system based on the number of Victory Points earned to date. Players are paired against others with similar scores, but in no case will a person play the same opponent during a particular session. Other pairing methods are possible.
  4. When Swiss pairing is used, players are ranked based on their final Swiss score. Elimination finals are normally not used.
Victory Point Division
If both players end with the same match point total, the match is a draw and both players earn 15 Victory Points. Otherwise, take the difference between the two match point scores and divide the Victory Points as follows:

  • 1-3 MP difference: 16-14
  • 4-6 MP difference: 17-13
  • 7-9 MP difference: 18-12
  • 10-12 MP difference: 19-11
  • 13-15 MP difference: 20-10
  • 16-18 MP difference: 21-9
  • 19-22 MP difference: 22-8
  • 23-26 MP difference: 23-7
  • 27-30 MP difference: 24-6
  • 31-35 MP difference: 25-5
  • 36-40 MP difference: 26-4
  • 41-45 MP difference: 27-3
  • 46-50 MP difference: 28-2
  • 51-55 MP difference: 29-1
  • 56-60 MP difference: 30-0