Originally Posted by
MadMojoMonkey
Yeah, it makes little sense out of context. It's pretty clear in the next paragraph what's going on.
For Alice, this means she has to call a 5-bet 60% of the time to prevent Bob from making a profit by 5-betting any two. So Alice's 4-betting range has to contain 60% value hands and 40% bluff hands. Now we know everything we need to know about Alice's 4-betting range. She 4-bets 30% of her opening range, and she uses a 60/40 value/bluff ratio. We'll summarize Alice's total optimal strategy below, but first we'll find out how often Bob should 3-bet.
We're not really really interested in Bob at this point, we're assuming that Bob 5-bets a given range, and we're finding Alice's appropriate response. In determining how she should respond to the 5-bet, we can see what must be her 4-bet range.
As always in GTO calcs, it's easiest to work backwards. So in order to know Alice's GTO 4-bet range, we need to know Bob's 5-bet range.
See in the last sentence how now that we understand Alice's 4-bet range, we can go back and analyze Bob's GTO 3-bet range?