backer contracts for cash games

[meatballAK]

Does anyone know what the details of common backer contracts are when you play cash games. I think its fairly apparent when you are playing tourney's. But it's much tougher for cash games. Let's say I decide I have 1k to spend and some one else throws in 1k. Does my backer own 50% of me? even if I never dip after putting in the first, say, 200?

Any answers or resources would be great. Thanks.