I often make wisecracks about "math guys" and their approach to poker. Now, I fully understand how important math is at the poker table, but if you focus only on the numbers without factoring in your opponent’s mood and playing style, you’ll come up with the wrong answer far too often.
Poker is a game of people, first and foremost. You could have all of the "poker math" down pat, but without the ability to read into how your opponents think and what they are likely to do in most situations, all of that knowledge becomes worthless to some degree.
Players like Phil Ivey, Erick Lindgren, John Juanda, and Jennifer Harman all understand the mathematics behind the game, but they rely heavily on their ability to read people in crucial situations. Their thought process generally isn’t, "Well, there is $600 in the pot and he’s bet $200. That means I’m getting 4-1 odds that he’s bluffing. I have no choice, I have to call."
It’s more like, "Does this guy have it or not? Does this guy have the guts to bluff me here? Would he even play that hand in this spot? If he did have me, would he bet $200 or would he bet more?"
Of course, they would definitely factor in the fact that they are being laid 4-1 odds on the call, but not before first doing some exploration and looking for clues that will help them make a more informed educated guess.
Conditional probability is what you should focus on if you want to reach the highest levels in poker. Static probability can get you only so far.