Anyone who really analyses the game should be able to pick against the spread at +1-3%. Some people can probably hit plus 5%.
Let's say Ana Kasperian has never bet a game in her life; she doesn't know Brett Favre from Ray Lewis (sorry if this isn't the case, Ana. It's an EXAMPLE! So I'm a little sexist. No great crime). She has precisely 50-50 chance of picking the game correctly. So add any deep analysis to that and you can up your percentage slightly.
The problem here, is the juice. With the house paying straight money on your win but taking 10% on every one of your losses, you will always end up on the downside after enough bets.
On to the Blackjack table. It's too much fun to play it when you are in Vegas to just GIVE UP! So moderate your play. Sit at a $10 table, have some drinks and enjoy yourself. Then take all the Benjamins in the back of your wallet over to
The Olympic Garden for some table dances!