Let's start with an example. In a full ring game, you find yourself in the cutoff position with Qc-Qs. Someone in middle position (MP) raises the minimum (2 big blinds) and you raise to 8 big blinds. The button and MP both call. The flop comes 3c-3d-4d. It's checked to you and you make a pot sized bet of 20 big blinds; only the button calls. Now, from previous experience you think that the button likes to take pots away. This player floats continuation bets on the flop then bets the turn if the other player checks. The turn comes a Kh. The pot has 65 big blinds in it, and your opponent has only 60 big blinds, which you cover. How should you proceed? You have one over card, a paired board and 2 possible draws out.
This is a precarious situation. Any significant bet appears to pot commit you. Say you bet 30 big blinds, and the button either pushes here or gets it in on the river. If that happens then the pot will be 155 big blinds with you needing to put in 30 more big blinds. That's over 5 to 1 pot odds; hard to get away from the hand. Any significant bet is half the button's stack. If you bet the turn and the opponent has a K or better, then you cannot avoid paying it off. If you want to avoid getting pot committed, you'll have to make a weak bet, but doing that invites a steal attempt from this player. While you may not be pot committed you set yourself up to lose the pot on a steal attempt.
Alternatively, you might check. You know, however, that the player will bet. Are you going to let this hand go to another steal? There's also a flush draw and a straight draw out, so betting weakly or checking gives a free card to beat you or a good card for the other player to steal the pot from you on the river. Leading the turn seems bad, and checking the turn seems bad. These spots are no fun, but you need a plan.
Part of the problem is that the button's hand range is enormous, so you can't get much of a read. The good news is, against this player you are in the lead the vast majority of the time. I'm suggesting the following probabilities for the hands the button might hold. For this player, one might include other hands, but this is sufficient for present purposes.
- Nothing, complete air (35%)
- Flush draw (30%)
- Straight draw (20%)
- A lone king (5%)
- Aces (4%)
- Quads/Kings (1%)
- Trip threes (5%)
Note that the overwhelming majority (85%) of the time, you are well out in front. So if these are the likely hands, how should you proceed on this difficult turn?
The argument for checking: if you check, you can induce a bluff from the pot stealer and push in over the top. A flush draw or straight draw will be pot committed and will call, but you are well ahead. If you bet then the button will fold at least 35% of the time holding nothing. Depending on the size of the bet, the draws may fold as well. So it could be that only the hands that beat you call your turn bet. On the flip side, 15% of the time, the button's bet will be backed up by a hand that has you crushed, and the button may just check behind with the draw getting a free card to beat you.
The argument for betting 40 big blinds or pushing: you give the draws a bad price. Sometimes flush draws will call in this spot, and if that happens, you stand to win a big pot. Unfortunately, most of the times that you get called here will be times in which you are way behind or drawing dead.
Given all of this, I think the check is the preferred play in this situation. Against a known pot stealer, you increase the range of hands that might bet here, giving you extra value. You run the risk of a bad card hitting the river, and you may have to fold there. That is the downside of this play, but in the long run, you will make more checking the turn than betting. Most players, even those who don't routinely steal pots, will bet a draw in this spot to try and take down the pot, since it appears that you have given up on the pot by checking. Against this particular opponent, however, I think you can expect a bet from any hand.
Assuming your opponent bets at this pot on the turn, and all the money goes in, the EV of checking is 81.26 big blinds. This means that with a current pot of 65 big blinds, a check against this opponent should win you 81.26 big blinds each time in the long run. By contrast, leading this flop for 40 big blinds or more will generate only 48.2 big blinds of EV.
In generating the EV for leading the turn, I assumed that your opponent would fold any hand that you have beat and only push in with hands that have you crushed. If this particular opponent is likely to chase the flush or straight draw, then EV goes way up. EV would then be 60.91 big blinds.
If your opponent isn't as likely to bluff the draw or chase your bet, then it appears to be better to check the turn and fold to any of the drawing cards hitting. Under that scenario, your EV should you check this turn is 58.67 big blinds.
Against this particular opponent, however, we assume that he or she is smart enough to not chase a draw, but aggressive enough to attempt to steal with any two cards. Since you have a good hand, you should take advantage of this tendency and induce a bluff. Obviously things change against other opponents. If your opponent is highly aggressive, as in he or she will call your preflop raise with the intention of stealing the pot from you, then checking the turn is an even better play, as the percentage of air hands climbs from 35%. The tighter your opponent is, the more you can narrow down the number of air hands and the more difficult this decision becomes as you must debate between winning the current pot or inducing a bluff.
A quick look at how I generated the EV numbers will shed some light on how to manipulate these numbers to get a better idea of how to proceed against different opponents. Under the ‘lead the turn scenario' I assumed that all the hands you have beat fold and that all the money goes in against better hands. So 85% of the time you just win the current pot (65 big blinds). 85% of 65 is 55.25. 1% of the time you will be drawing dead, so in those cases you lose 60 big blinds, but that is only (-.6BB) for expected loss. The other 14% of the time you need to draw to a set and so only improve 4.3% to win 125 big blinds and lose 60 big blinds 85.7% of the time. 14%x4.3%x125BB=.75 and similarly 14%x85.7%x(-60BB)=(-7.2BB) and now you just add these numbers up. 55.25 - .6 + .75 - 7.2 = 48.2 big blinds. To do further analysis you'll need to know the odds of your hand holding up against other hands and try that out against various assumptions regarding likely hands your opponent might have.
In today's case, against an aggressive opponent who likes to try and steal pots, you should let him or her make the normal play and pick off the bluffs. Your EV is better and your bankroll will move up in the long run.