User:Fishysua/Clock
A Clock is a measure of the time until a certain event occurs, usually a player losing (connecting this concept with that of the fundamental turn). A clock is almost always measured in turns.
Creature clock
A Creature Clock is given by
C = Ceiling(R/P) + M + S
where C is the clock, R is the responsibility, P is the creatures power, M is the creature's mana cost, and S is any adjustments due to special abilities, most usually -1 due to haste.
Responsibility
Deck clock (or goldfish)
A Deck Clock or goldfish is a fictitious opponent with 20 life that never casts or controls anything during a game. It was invented during a time where people were starting to ask themselves how fast their deck were. There are primarily two different goldfish rates to which players refer. The first is the idealized goldfish, where the player draws the cards in his or her deck in the way which deals 20 the fastest. The second is average goldfish which is usually estimated using a simulation. The goldfish is part of tuning a mana curve.
Active goldfishes
It later became clear that a passive opponent is a poor test of a deck. So improvements were attempted. One of the best known of these had no name on it's own, it let the opponent control a 2/2 flying creature with "0:regenerate" and a 3/3 trample creature. Both must attack you each turn. Another active simulated opponent would play a Plague Rats each turn thereby escalating the threat each turn and also simulating a natural process of recovery.
Specific tests
Some people made specific tests that were designed to test certain decks to their fullest. If a deck had problems with counterspells the test would have counterspells. If the deck had problems with weenies it would have to face weenies. These tests would often take the shape of a card that the opponent would start with in play. For example "The swarm lord" a white 2/4 creature that each turn put a 1/1 white creature into play. Mana costs were irrelevant because it started in play. A standard was to use two such cards to reflect a certain decktype that you wanted to play against.
Random tests
From creating 2 cards to repressent an opponent there wasnt far to shuffle random cards together to reppressent rogue decks. As a general rule there were two sets of cards, one where all cards could deal 2 damage or more each turn and one where they deal 3 damage. All cards would have abilities that made them repressent one half of a known and feared deck, and by fighting against two random testcards your deck would face a solid challenge. The ammount of damage was chosen to reflect the general speed of the fastest decks. At that time most decks could win consistently at turn 4 against a goldfish, so the goldfish "cards" were modified to do exactly the same in combination while creating other game-like problems.
Present
The most complicated of tests have fallen by the wayside, as game popularity and MTGO have made it possible to find actual opponents with great ease. The simplest tests, the idealized and average goldfish; however, still have a strong preliminary role to play.