Dark Confidant

Dark Confidant (also affectionately known as "Bob"), released in Ravnica: City of Guilds, is a rare, black creature that allows its controller, at the beginning of his or her upkeep, to effectively draw an additional card at the cost of paying life equal to the card's converted mana cost.

"Bob"
Dark Confidant is so nicknamed after Bob Maher, Jr., its creator. Maher won the right to design and be immortalized in his 2004 Magic Invitational submission. The card's flavor text alludes to Maher's epithet "the Great One". Dark Confidant was reprinted in Modern Masters.

The original submission of Maher involved poison counters.

Grand Prix Columbus

 * Steve Sadin's Flash Counterbalance 1st Place GP Columbus
 * Max Tietze's Fish 4th Place GP Columbus
 * Michael Belfatto's MBA 8th Place GP Columbus

Worlds 2007
The following decks all had a record of 4-1 at Worlds 2007:
 * Camargo's sideboard Worlds Legacy
 * Vitor Dama de Rosa's sideboard Worlds Legacy
 * Komuro's sideboard Worlds Legacy
 * Lybaert's maindeck Worlds Legacy
 * O'Mahoney-Schwartz maindeck Worlds Legacy
 * Wu's maindeck Worlds Legacy
 * Yasooka's maindeck Worlds Legacy
 * Kapalas's maindeck Worlds Legacy
 * Nicosia's maindeck Worlds Legacy
 * Stienaa's maindeck Worlds Legacy
 * van Heeswijk's maindeck Worlds Legacy
 * Thompson's maindeck Worlds Legacy
 * Meulder's maindeck Worlds Legacy

Pro Tour Honolulu

 * Olivier Ruel's Hand in Hand Honolulu
 * Ruud Warmenhoven's Orzhov Aggro Honolulu

Statistical analysis
Dark Confidant's effect can dramatically change the way a deck wants to play out. Drawing an extra card per turn should lead fairly directly to playing an extra card per turn, while simultaneously reducing the number of lands required to make each land drop. A turn by turn analysis follows, so that it can be compared with the theoretical basic curve. Note that this analysis is identical to the one which would occur for Howling Mine and several other cards. The first analysis shall assume we are on the play.

First turn: The Dark Confidant cannot affect our draw on the first turn so this is the usual minimum 9 one-drops to have drawn one and similar 9 lands, totaling 18 cards.

Second turn: Again, the Confidant does not affect our draws so we still have the "basic curve" which tells us we want 8 two-drops and 15 lands, bringing our running total to 32 cards.

Third turn: Henceforth, we will assume that we have drawn and played a Confidant on turn two to give the most extreme variation from the basic. This turn, having drawn two cards we want to play two spells and make our third land drop. So we should have our third land, second one-drop and second two-drop in these 10 cards. Now we have 12 one-drops, 12 two-drops, and 18 lands, for a total of 42 cards.

Fourth turn: This turn we play two two-drops and one land, which means we desire 20 of each in the deck, for a total of 52 cards.

Fifth turn: Another land, two-drop, and finally a three-drop lead us to 22 two-drops/land, and four three-drops, totaling the deck out at 60 cards.

Curve comparisons
60 cards, play first

Basic curve

9 one-drops, 8 two-drops, 8 three-drops, 11 four-drops, 24 lands.

"Confidant curve"

12 one-drops, 22 two-drops, 4 three-drops, 21 lands.

The "basic curve" makes one play per turn for the first five turns, totaling five plays while the "Confidant curve" makes a total of eight plays over the same amount of turns. The "Confidant curve" also manages to make the fifth land drop with fewer lands.

"60 cards, draw first"

"Basic curve"

8 one-drops, 7 two-drops, 6 three-drops, 5 four-drops, 9 five-drops, 25 lands.

"Confidant curve"

11 one-drops, 21 two-drops, 4 three-drops, 3 four-drops, 21 lands.

Here the basic curve again makes one play per turn, this time for six turns, whereas the "Confidant curve" goes 1/2/1+2/2+2/2+3/1+4 missing the sixth land drop just like the "basic curve". The "Confidant curve" here makes 10 plays over 6 turns.