At the recommendation of many people on this forum, I just started reading through Professional No-Limit Hold 'em. I'm only about 60 pages in so far, but I came across a sample hand that I just don't understand. Most of the sample hands so far are for $1/$2, which I play. This one is for $5/$10, but hopefully I can still learn something from it.

It's on p. 57. The opponent who checkraised all-in is loose. So he could easily have AJ, 99, 77, 97, J9, or flopped a straight with T8. When he checkraises all-in, I'd probably put him on a 2 pair.

The authors say, "Although you may be beaten, you expect to win money when you get all-in." And say you'll learn how you know that later in the book.

I didn't want to skip past this without understanding it, because if this were me live, I don't think there's any way I'd call. But apparently calling is correct. Can you explain why?

Thanks!

A better description of the hand would be helpful, and without knowing what hane we have, it's hard to comment specifically.
Having said that, it's all about ranging the opponent.

I'm going to assume that we have an over pair (Aces or King), we raised pre flop to 5x, got two callers, we bet the flop for 2/3 - 1 PSB, and he check raised over top for ~4x our bet on a J97 board.

If that is the case then the entire range of hands that he might put stack in here with is:
AJs, AJo, KK, QQ, JJ/99/77, J9s, J7s, 97s, T9s, Ah9h, Kh9h, Qh9h, T8s, JTs, 98s, 87s.
And maybe a 5% complete bluff frequency.

If this is the case, then you want to take a program like PokerStove and put in that flop, your hand, and his range of possible holdings and figure out what our equity is vs his range. What we find is that we have 55% equity against that range. If we modify some of those hands, we will see our equity change. We also need to consider what sort of odds the pot is laying us. I.e. what the return on our call can result in.

The pot has 90bb in it, and we need to call another 45bb. So, we are getting 2:1 on our investment.
If we changed his range to something stronger that doens't have as many draws in it, and found that we were behind his range 35%:65% we could still profitably call as we are getting a 2:1 return on our money, however, we are slightly better than 2:1 to win.
So, 35% of the time we earn 3x our bet, and 65% of the time we earn 0x our bet.

This results in an average return of 105% of our bet. Which means that we have a positive end result from calling here even though we would still lose >60% of the time.

Having said all of that, these are concepts that can take a while to get a firm grasp on.
Reading the many stickies in this forum can be a great start. Posting actual hands that you play be another good step.
Discussing poker hands with any friends that you have that might play will also be a great way to learn new things.

Thanks. Sorry, I didn't post the exact situation because I figured people with the book would read it from there. You were pretty much on the money. But for others:

"You have QsQc in a loose live 5/10 game. You have the short stack at $500. Two loose players limp. You raise to $60 and both call. The pot is $195. You have $440 left. If you flop an overpair, your plan is to commit.

The flop comes Jh 9d 7h. Both opponents check. You bet $200. First player folds, second checkraises all-in."

I guess I didn't give the possibility of a flush draw coming all-in. With that bigger range like you listed, I can see a call making sense.

This is in a chapter called The Fundamentals: Commitment, so this example is teaching about commitment. When I bet $200 (pot is now $395 and I have $220 left) and he raises me all-in, I'm getting $615:$220 or 2.8:1 odds. I guess I'm not getting the commitment concept they're teaching with this hand... it seems to have to do with the size of the pot relative to my remaining stack. But how is that different than pot/implied odds? Because when you're all-in on the flop, you know your exact odds and know you won't have any more chips to put in on later streets?

Commitment (while an overused term, and often incorrectly applied) as they are refering to it here is very close to the idea of pot odds.

The reason that we are commited to the pot is not that we have invested a large portion of our stack, but that the amount of money that remains for us to call (because of our stack size) is small compared to the size of the pot and we expect the villain to show up with a range of hands that (along with the price in the pot) we are gaining a positive expectation by making a call.

Lets change the exmaple just a bit: V is now the short stacked person at the table and you cover with $10,000. You make the same open. You make the same cBet with the same hand, and the same board texture. Now the villain goes all in but this time he started the hand with $500 so he's shoving for $240 more into the pot. At this point we are still typically going to go with the hand and it clearly has nothing to do with the amount of our stack that we have put in. While we have invested a time % of our stack (2%) the amount of money that we need to call to complete the action is very small compared to the size of the pot.

Side note: Commitment isn't a thing in a cash game though.
You are never commited to any pot in a cash game ever.

It always comes down to, what is the villains range in this spot?
What price am I getting on my wager from the pot?
Are these two items combined together going to result in me having a positive expectation?

If our villain raises the river, and we have to call $5 more into the pot of $5,000 ar we commited? If we have the nut low, and can never win the pot, and can never chop the pot, then no we are not. If we have the second nuts, but he's stupid and he turns over the nuts, then no we are not.

Yeah, basically. You don't have any RIO because there's no more money left to bet.

I'm currently re-reading PNLHE myself. The point this hand is getting across is you were supposed to plan for commitment pre-flop, and with a 2 SPR going into the flop, you should be committed unless an overcard comes, especially against a loose villain, because at that stack depth you'll be getting it in against draws and TPTK-type hands plenty often enough to make up for the times V has you beat in this huge pot. When you bet $200, it was because you were planning on committing. You'd have preferred a call, and V to call a turn shove, but because you're committed, you call it off because the pot is laying almost 3:1, i.e., he doesn't have to have TPTK or a pair+draw very often for calling the shove to be profitable. That it's 5/10 is relevant because you're much more likely to see a CRAI (semi-)bluff at 5/10 than 1/2 or 2/5.