But it’s a totally different story in a big game. If I raise it $3,000 or $4,000 and the other guy and I have a lot of chips on the table, he’ll be a little more hesitant about raising me now because he knows there’s a very good chance I’ll play back. The guys I play with know that when I put my children out there, I don’t like to let them drown.
—Doyle Brunson, Super/System2, p. 394
A few days ago, I played a cash game session at the Meadows ATM. During the game, I saw an example of what is probably among the top five poker leaks, at least among recreational players—calling with a hand you are fairly sure is behind solely because of the amount of money already invested in the pot.
The hand went roughly like this. There was a straddle, and just about everyone in the room limped into the pot. Straddler raised to $24, and there were four callers. The flop came out highly coordinated—something like 9h8h8d. Straddler led out for $75, and got two callers. The turn was the Jh. Straddler led out for $125, with both players immediately going all-in for ~$800 more and ~$100 more. Now the big stack had never once shown down less than the second nuts when putting big money in the pot, while the other player was an uber-tight older nit. Straddler thought a minute, then said, "Well, I've already put most of my money in the pot, I have to call," and called for his last $150. Sure enough, the big stack had 98 for the flopped boat, while the old nit had the nut flush. The boat held up for another monsterpotten to the big stack. Straddler claimed to have held AhAd, and left after busting on the hand.
Now the big leak in this hand is the Straddler's thought process. He was fixated on the size of the pot and the fact he had committed a lot of his chips to the pot. The problem is that this fixation on the pot size and prior action blinded him to the reality that he was likely either drawing thin or dead. In economics terms, the money already committed to the pot is regarded as a sunk cost. A sunk cost is essentially a prior expenditure that cannot be recovered. For example, a developer decides to build a casino on the Las Vegas Strip. Building commences, and the project is 50% completed, but then the economy tanks. The projections for income from gambling, conventions, shopping, and other resort activities are no longer valid and must be revised. The new figures show that the projected income stream from the completed casino will not meet the additional expenses needed for completing and opening the casino; in other words, the project cannot be finished at a profit. A rational developer would abandon the project, despite having already invested tens or hundreds of millions into the project. The money invested prior to the decision point is irrelevant to the decision regarding whether to complete or abandon the project. If the additional investment needed to complete the project will not result in a profitable venture, then there is no point in making the additional investment.
Turning back to poker, the amount you personally have invested in a pot is never a valid consideration governing your future play in the hand. Either you have correct odds to call vs. your opponents' range(s), or you don't. The amount you have "invested" or put in the pot up to the decision point is irrelevant; it is a sunk cost. The past is past, and that money is now part of the pot; it is no longer "your" money or "your" investment. Reasoning that you "have to call because you already put in $X" or "it's an easy fold because you've only invested $Y" is a major leak. A smart poker player will look only at the total pot versus the wager he is facing (and future implied wagers, where relevant) when making his decision.
The problem is that many recreational poker players, because they are loss-averse, will improperly factor the sunk cost of their prior wagers into their decision making process. These players often improperly invoke the concept of being "pot-committed" to justify their ultimate decision to make a bad call. Let's look at an example. You flop a monster draw with QJs, but get to the river and have Queen-high after missing your draws (let's ignore your ineptitude in failing to get all-in on the flop). The river paired the board, so you decide to take a stab at the $500 pot, betting $300. Your opponent, a rock, goes all-in for $400. It's $100 to call into a pot of $1,200. You're getting 12:1 on the last call, but is your hand ever good here, let alone one out of every thirteen hands? Are you truly pot-committed here? Calling in these situations is a terrible leak, yet many recreational players make that last call because they're fixated on all the money they've already put into the pot.
There are circumstances where loose calls with marginal hands are warranted, but those loose calls must be justified by relevant considerations: your opponent's likely range based on his betting line and your reads, coupled with your knowledge of your opponent's playing style (particularly whether he is prone to bluffing or making value bets with marginal hands). Basing your decision to make a loose call on the fact that you've already put a lot of money into the pot is throwing good money after bad. Once you've paid enough money to know you're beat, why voluntarily pay even more for the privilege of losing the pot? Making a habit of making these bad loose calls will eventually sink your bankroll.
"Don’t make loose calls and hopeless bets to avoid giving up on the pot. It’s okay to leave your kids out there sometimes. Maybe they have soccer practice today."
—Schmidt & Hoppe, "Don't Listen to Phil Hellmuth", p. 112
If you're sunk, it's silly to go down with the ship.