Re: "Provably fair" question

So your saying long as the hash that is used is from a block and not a transaction is ok?

Not entirely. The block reward is 25 BTC. If I'm a miner and find that a block I just mined makes me lose a 1000 BTC bet it would possibly be in my best interest to withhold that block and let someone else mine a different block.

That still makes it probably fair

It is provably fair.

And no, miners get an advantage, which is against being "fair" (though I don't think someone would actually use it to his advantage) But using the term can well be questioned.