Big Mistake vs. Small Mistake

[RocketManJames]

In poker literature and discussion, we often hear about "big mistakes" and "small mistakes." A small mistake would be calling a final river bet when it looks very unlikely that you're a winner. A big mistake would be *not* calling that final river bet and then finding out that you would have won had you called.

If we think of this in purely EV terms... is folding on the river when it looks fairly unlikely that you hold a winner, a truly "big mistake?" Say the pot holds 7 bets, and an opponent bets. Now, if you call, you stand to win 8 bets and lose 1. At this point, if have greater than a 12.5% to win, you should call. Now, say that the true % is 15%. If you fold, you have made a mistake. There is no doubt about that. But, is it really a "big mistake?" I understand that if you make small mistakes frequently, it becomes a big leak in your game. However, I am more curious about a single mistake and how large it can really be.

How often do you really commit a single "big mistake" in this game due to folding? It seems that if you had a much higher % of winning, a call would be nearly automatic. I figure if you were facing a final river bet, and you were in the 30+% winning chances range, you wouldn't even ponder much about whether to call or fold.

Anyone follow? What do you all think?

-RMJ

[Al_Capone_Junior]

In your example, if you were getting 8:1 and KNEW that you had a 15% chance of having the winner, then you would by definition be making a mistake, and it would be wrong to fold, regardless of the size of the mistake. However, often your chances are much higher than this. It's usually quite hard to say you are more than 87.5% certain that you're behind, thus you call. Think of your heads up opponent's EV here for a bluff if he knew you would fold 15% of the time, he would be crazy NOT to try and bluff you.

Losing a big pot because you incorrectly folded might only be a small theoretical mistake (as per your example) but that pot is no doubt 8 hours or so worth of EV for the game you are in, vs. only 1 hour EV if you call and lose. You just can't be making those kind of mistakes. As the pot gets bigger this becomes even more important. Being right only once can make up for many times you were wrong and still show a significant profit.

al

[Louie Landale]

Right on. One of the few "mistakes" the authors have made is botching this notion. If your chances are really 15% and you need only 12.5% to justify a call, its only a "big mistake" in the divide-by-zero sense. But its a "small mistake" as far as your EV goes. Same goes with giving "free cards". If the opponent has only 2 outs and won't call, you are giving him only 1/24rds of the pot by checking. If there are 4 bets in the pot thats giving him about 1/8th of a bet, no big mistake at all.

I think "big mistakes" are those that cost more than a bet. "Disasters" are those that cost more than 4. Failing to raise 6 opponents with a big draw is a clear "big mistake". Folding a fair sized pot against someone who is probably bluffing is a "Disaster".

- Louie