Unique situation - did I make a huge mistake?

[BCVI]

Hello, everyone. This is my first post; I hope I'm in the appropriate forum.

Last night I was playing at my friend's regular home game and I found myself in a unique situation.

We were about half way through a NLHE single rebuy/addon tournament (past the rebuy/addon period). There were 7 players remaining (top 3 got paid). The blinds were 100/200 and the relevant chip stacks were:

BB ~ 1700
Player A (under the gun) ~ 6700
Me (2 to the left of Player A) ~ 7800

Player A raised to 600. The next person folded. I called with KJ. The next 3 people folded. The BB reraised allin. Player A called the BB, and then incredibly forgot that I was still alive in the hand and turned over his AQ. Even though I was behind I figured I had the odds to make a correct call (especially since there was a chance that both the BB and Player A had an ace), so I called.

The flop came K74 (rainbow, I think, but Player A didn't have a flush draw, for sure). Player A checked. Now, I know that in this situation, the normal strategy is to check down the hand and try to eliminate the short stack. But in this unusual situation where I knew that my opponent completely missed the flop and I made top pair, I decided to bet allin.

To my amazement, Player A called. I turned over my cards and the BB also turned over AQ. One of the two remaining aces came on the turn, so I lost most of my chips in the side pot and Player A and the BB split the main pot.

In retrospect, the only ways I could have won any money with my allin bet after the flop is if:

A) I went all, Player A called (which obviously is not very likely to happen, but incredibly it did in this situation), and my top pair held up,

or

B) I forced Player A out with my allin bet and the BB held a hand such as QQ that would have lost to me in the end (but we would have both lost if Player A had still been in the hand).

So, what do you think? Did make a mistake by betting after the flop? Should I have checked it down even though I knew I had Player A in a huge hole after the flop?

Thanks in advance for your responses.

[onesandzeros]

yes, you check it down.

[TomCowley]

Checking it down, when you're still out of the money, is generally wrong. Checking it down here is terrible (like everything that guy says in any forum on here). The only way you MAKE money over the check-it-down value is if he makes a terrible call, but it's easy for you to lose the entire pot if an A (or straight, or QQ) peels, since BB could easily have a pair and be drawing to 2 outs. Avoid losing the pot by giving your opponent a free card. He made a horrific call and sucked out. So it goes.

Depending on the opponent, I can see either shoving or betting ~2000 (and then shoving the turn) to milk him. You might can even find an argument for checking and then betting a blank turn. Checking with the intention of checking a blank turn is 100% wrong.

[onesandzeros]

Tom, go reply to my post in the other topic instead of trying to attack me over something so trivial. I misread it and thought they were 3 handed. My bad OP.

[TomCowley]

Then you're still completely wrong, and it's not a "trivial" mistake. It's the guy's first post and you're giving him completely incorrect advice with no analysis. You don't check it down 3-handed.

Because there are relatively few hands the BB could hold that will beat you but lose to A when A beats you, the benefits of letting A bust the BB (about +2.8% equity) don't occur often enough to offset the risks of losing a pot to A that you would have otherwise won (about -6.2% equity).

[flytrap]

The only thing you did wrong was when you called an utg raiser with KJ. Checking the flop with the intention of checking it down is bad. If you're slowplaying or something, then check and bet the turn.