You can possibly if you pull the right draw win on Turn 1. Check it out.
Turn 1: Swamp, Dark Ritual, Dark Ritual, Dark Ritual, Wall of Blood, use Wall of Blood's ability to Pay 1 life to give it a +1/+1. Pay 19 of your life. So Wall of Blood is a 20/20 then cast Essence Harvest. Dealing 20 direct damage to your opponent and you gain 20 life. Game over, 21-0. Turn 1.
You can play this extremely fast with a good draw, T1: Swamp, Blood Pet. T2 Swamp, Sac Blood Pet cast Dark Ritual. Cast Sanguine Bond. T3: Swamp, Dark Ritual Cast Exquisite Blood. T4: Pirahna Marsh, , Taste of Blood, Sorin's Thirst, Sign in Blood, Blood Tithe, or (Blood Artist and Sac'ing a Blood Pet) WILL ALL END THE GAME. Ok so thats the good draw.
Other ways to win. Ok so other possibilities and deck strengths are... If you only have Sanguine Bond in play, you can cast blood tribute and end the game if you control a vampire which there are 6 possible ones to cast. They all serve a specific purpose, Blood Seeker will keep your opponent from being able to cast any creatures once the combo hits the board. CONTROL. Blood Artist's will keep your opponent from being able to Sac or lose any creatures on the board once the combo is out. If the combo is out and a creature goes to the graveyard, you win. CONTROL. Bloodthrone Vampire, ok so basically he is useful for the times you may sac Blood pets and Blood Vassals for mana, and its a vampire towards a possible Blood Tribute. and lastly, Blood Reckoning. If you have Blood Reckoning on the board with the SB/EB combo. Your opponent can't attack you. CONTROL.
So not only does this deck have the ability to suddenly end the game, you can keep your opponent from Attacking, Casting Creatures, Sacrificing Creatures.
In multiplayer its awesome as well, the leechridden swamp can end a multiplayer game for one mana if the combo is out. So can Blood Tithe.
Tell me what you think?