Beginning Theory questions

[wacki]

I've been ready sklansky's Theory of Poker and I there are a few things I can't figure out.

Question 1) check - raising: Sklansky says you check-raise monster hands. Is there any other reason to check-raise? If not then wouldn't it be a dead giveaway that that person has a monster?

Question 2) Page 126 in TOP. Sklansky says the odds of turning 2 pair in 5 card draw into a full house are 1 in 9. Since 2 pair has 4 possible cards to turn it into a boat, wouldn't it be a 1 in 12 chance? 4 outs / 47 unseen cards = 1 in 12 1/4

Question 3) page 106 of TOP
An opponent has a 52% chance of semi-bluffing & 48% chance of having a good hand. You are a 6-5 favorite to beat him if he is semi-bluffing. If he's not semi-bluffing then you are virtually locked out. Your opponent bets. Sklansky says many pro's make the mistake of calling, but unless the pot is large you must fold. He says you would only be winning 29% of the time and therefore you would need 7-3 effective odds, which is highly unlikely in early betting rounds. How did he come up with 7-3 effective odds?

[Bozeman]

odds are not the same as probability of winning.

odds = prob losing:prob winning, hence the 7:3 (71:29 to more precision) on the last one.

For 47 unseen cards, odds of fulling are 43:4=10.75:1, so he must have been assuming something else (such as none of your cards in opps. hand gives 38:4=9.5:1).

Just because you check-raise monster hands (sometimes) doesn't mean these are the only hands you CR.

[tubbster]

Just re-read these chapters this morning...how convenient.
1. One example would be if you are on a flush draw with many people in the pot, and you are sure the person to your left will bet. It's 4-1 to make your flush, so you let that person bet, call it (b/c of pot odds) and raise it if at least 4 people are still in. You can assume most will stay in for one more bet. Thus you get two bets with positive EV instead of 1. Another more rare example is if you are UTG, think the last to bet has you beat, but think you have the second best hand. You check, hoping to raise when he bets and drive everyone else out. Both of these are at the end of the checkraising section
2. He says you know what your opponents have at the beginning of the example.