Okay, this post attempts to carry out the mathematical comparison between the bet/call flop line and the check/call flop line, to see whether the value lost from the flop checking around is compensated for by the value won when we are able to get away from our hand on the turn (Say, when the board pairs and an opponent shows aggressions). Here goes:
Tl;dr: The aggressive bet/call line is favored to the passive check/call line.
If we check the flop, it is usually going to check around, and we are going to miss value from worse flush draws and worse combos draws which would otherwise call a flop bet. How often will it check around? Well, it will only check around if no opponent holds a hand in the two categories: C1 = {JJ,TT,QK} or C2 = {AJ,AT,JT}. These make up 18+21=39 combos out of ~1300 combos, so the probability any one player holds such a hand is 39/1300=3%. So, the probability one of the 9 players holds a C1 or C2 hand is 1-(0.97)^9 = 24%.
Assuming the flop is bet (again, 24% of the time), the cautious route of x/c on the flop will be followed by turn action. If the turn pairs the board, we can get away from the hand on the turn and preserve our stack -- we save like $250 when this happens. But, given that our opponent has bet the flop, the turn will pair only 10% of the time (it's a bit less than the usual 12% because the opponent will hold blockers due to their 2pair and set combos).
So 10% of 24% of the time, the cautious route saves us $250. The EV gain for the cautious route in this case is roughly (0.1)*(0.24)*250 = $6.
Where else does the cautious route save us money except in the situation where the turn is paired? It's not clear to me that there are any other situations where it is beneficial. If the turn is a blank (like 4
), we will be forced to call any reasonable-sized turn bet, up to the size of the pot (our equity against the range of C1 and C2 is 33% on a blank turn). We're gonna lose an additional 100-150 dollars, and at that point, we may feel pot committed on the river and have to call of our last $100. If we hit our flush or straight on the turn, we're going to be in the awkward position of trying to get stacks in from out of position when our opponent is the aggressor -- clearly there is no benefit to the passive line in this case.
On the other hand, the cautious route loses money relative to the aggressive bet/call flop line in every situation where the flop checks around (this will happen 75% of the time) and where one of our opponents has a hand that we crush -- let's call these hands C3. There are like 12+ combos of worse flush draws out there (hands like 6
8
,7
8
, etc.), 12 combos of AQ, 12 combos of QJ, 9 combos of KJ, 12 combos of QT, and some fraction of the 16 combos of Q9 (I don't know if players at 1/2 NL love calling EP raises with trash hands like this, but my guess is they do, so maybe close to the max 16 combos) -- all of these hands would call a $40 flop bet. How often are these C3 hands in our opponents range? -- for a very conservative estimate, we are going to say 60 combos of C3 hands -- so, 60/1300 ~ 5% chance of a C3 hand per opponent, and 1-(0.95)^9 = 36% chance that one opponent has a C3 hand and can call a flop bet. We're an 85-15 equity favorite against the C3 hand range.
So the value of the aggressive betting route relative to the cautious route is at least
(probability no opponent has a C1 or C2 hand)*(probability some opponent has a C3 hand)*(equity advantage against C3 hand)*(size of bet) =
(0.75)*(0.36)*(.85-.15)*40= $7.5.
Plus, if one of our opponents hits their draw and it is second best to our completed draw, we can try to squeeze additional money from them on the turn (e.g., in flush over flush, or straight over straight+redraw situations). These turn bets will be much larger in proportion to the size of the pot, due to our flop bet.
It seems like the value of the aggressive route will end up being considerably more than $7.5 (and anyway, certainly greater than the $6 benefit of the cautious route).
The aggressive route also has the benefit that we never have to worry about the opponent bluffing us off of the best hand -- e.g.,we might get owned if we hit our two pair on the turn, and one of the 5 opponents with position on us decides to turn their hand into a bluff and represent the Queen. In general, it is for this reason that we prefer to take aggressive betting lines in EP -- it negates the opponent's positional advantage.
Last edited by aisrael01; 10-23-2018 at 03:06 PM.