The check call lead out on the turn can be attacked.
A few weeks ago I played an interesting hand in a three-bet pot at the Bicycle Casino in Los Angeles. The game was $5-$5 and had a maximum buy in of $1000. I was doing well for the session and sat with $2200.The villain in the hand had had a $5000 stack at one point but had lost a bunch of pots and now sat with just $1000. It was pretty obvious to me that he was a fairly recreational player as he had drastically overplayed hands when he sat deep. It was also obvious that he was a little flustered.
I sat to his immediate left and in the hand in question it was folded to him in the cutoff and he made a standard open to $20. I looked down on the button at 5♥ 4♥ and decided to three-bet to $70. Against an early position raiser I may just flat or fold this hand but in this configuration I felt that this weaker holding would do better if played headsup. I also might get an immediate fold preflop. The blinds got out of the way and the villain called. The flop came down A♥ J♠ 9♠ and my opponent checked. Since this flop should hit my three betting range and also because a lot of players at this level do not pay attention to positions (the fact that I could be wider as I was on the button three-betting his cutoff open) I decided that a continuation bet of $80 was in order. I also had backdoor straight and flush draw and planned on double barreling cards that would improve my draw.
My opponent called rather quickly and the turn brought in the 2♥ giving me a straight flush draw. Now, unexpectedly my opponent led out at me for $120. Since the deuce was rather irrelevant for the most part, with the exception of A2 suited, I figured the turn did not help him. I also thought that if he had flopped something big like a set of 9s or AJ, that he would have either check raised the flop or the turn, not take a check call, lead line. Also, my opponent called rather quickly preflop causing me to discount a lot of AK type hands, which might four-bet or at least take some time to think about what the proper action would be. To me, this lead out represented a lot of one pair ace type hands that were “betting for protection”. With the equity that I had in my hand (12 outs versus an ace) I decided that the best play was to shove all-in and put a ton of pressure on my opponent. “Damn”, he proclaimed immediately after I made the bet and visibly got uncomfortable. He took about one or two minutes and finally folded QQ showing it to the other side of the table.
Besides the fact that this was a really ridiculous line with QQ—as he gets all hands worse to fold and only better to call—his line was consistent with a medium strength holding. The problem was that he left himself open to an aggressive semi-bluff that forced him to fold. If you are playing out of position against a good aggressive player, remember if you play the check-call, lead line on the turn with a medium strength hand you are opening yourself up to being punished. However, if you do this occasionally with some strong hands you can get someone like me to bluff the entire stack off thinking that you are weak.