[RobertJohn]

Great review. I'm through the first couple chapters, and like you said, there is some practical advice in there.

from pg. 100:

of the connectivity categories the only situation that we are possibly unhappy with is when a made straight is already possible

Here the author is describing your equity given different flop textures (according to # of possible straights and straight draws possible on the flop) and number of opponents when you hold a set.

Although he says the probability your opponent has a made straight is small on a 765 board when you hold 55 (the assumption is that your opponent has a lag/wide range), when you can narrow your opponents range after the flop, your equity changes drastically when a made straight is already possible. This is heavily dependent on how high the board is too.

The excerpt reminds me of a hand I played the other day, which illustrates this point very well IMO:

I was in a $2-$5 B&M NL game.

I had a conservative image and had been playing tightly due to a bad run of cards. I was dealt QQ in the CO and I raised a late/middle position open-limper.

The limper had been playing very straightforwardly and was quintessentially tight-passive.

We both had > 200BB stacks.

It went HU to the flop with ~ 10BBs in the middle.

The flop came KQ9r, giving me three Queens.
He checks and I bet 2/3 pot, and he c/r me.

Even though I have a set, my equity is not as good as you might think against this specific opponent’s range because we can narrow his likely hands pretty well:

Since he is straightforward, we can probably eliminate AA and TPTK from his range since he didn’t open-raise preflop from late-middle position. Ditto for 99 (although sometimes I’ll limp in with 99, I saw him earlier open-raise with medium PPs to protect them).

Q9 or K9 is very unlikely because he is tight/passive. He would not call a raise OOP with those hands, possibly if they were suited, but not likely.

KT or KJ or QJ are also unlikely for similar reasons (not likely to call with a garbage hand OOP) but more importantly he would probably not take such a strong line as a c/r against me with my image. He would probably c/c or lead. Check-raises with deep stacks OOP are monsters with this guy, not semi-bluffs.

KQ is also very unlikely b/c there are only 3 combos left. So, after all this deduction (and pretty bold assumptions), we get left with 3 combos of KQ and 16 of JT for his range.

On the flop, I have 43% equity,
If a brick turns, I’ll be ~ a 2-to-1 dog.
If another brick falls, I’ll have 16%.

Granted, these are very strict assumptions (and against most opponents, not applicable), but against a tight/passive, straightforward player (and a physical read) his most likely hands by far are KQ or JT.

Sure, we’re not folding the hand b/c the implied odds are ginormous if he’s sticky (and our equity is too good even if he has a straight most of the time), but if we wiff the turn and he keeps hammering into a small pot, we have to think about changing our gameplan from the normal set-attack mode.

The mathematical material and resulting practical advice the author shares in the few chapters I've read have been pretty useful in getting me to think about hands more precisely.