A lot of small-stakes poker players make the habitual mistake of betting too small, which costs them a substantial amount of money in the long run. The following hand is a good example of how underbetting can be costly.

In a $1/$2 no-limit cash game, six players limped around to our Hero in the small blind, who raised to $12 out of his $100 stack with Q Q.

Hero should have made a larger raise. By betting just $12, he is destined to get a large number of callers. When you give your opponents excellent pot odds by betting too little, rarely are they making a mistake by calling. You profit in poker when your opponents make mistakes, not when they play well.

To my surprise, only three players called. The flop came 9 7 5. Hero bet $20 into a pot of $56.

While a small bet is acceptable, I would have bet larger, perhaps $32. This is a flop where Hero is almost certain to go broke against a flopped set, so his main goal should be to extract maximum value from worse made hands and draws. His bet of $20 gets a bit of money into the pot, but most made hands and draws will call even more. Betting $32 also would allow Hero to go all in on the turn for a little less than a pot-sized bet if one player calls.

Two opponents called, and the turn was the 2. Hero bet $25 into a pot of $116.

As with the flop, Hero should have bet larger, this time shoving all in. By going all in, he prices out the various draws while also extracting value from fairly strong made hands such as J-J, A-9 and 9-8. Betting only $25 gets less money into the pot against the strong hands while giving the draws acceptable odds to stick around to see the river card.

Both opponents called. The river was the A. Hero checked.

I liked this check. The ace would probably only help an opponent who held A-9, A-7 or A-5, and Hero would now have a difficult time extracting additional value from middle pairs, since the ace is a scary card for them. In this instance, a player with a middle pair would check behind, meaning that when Hero faces a bet, he is probably up against either a rivered two pair or perhaps a busted draw.

The first caller went all in for $43. The second caller folded.

This was a tough spot, but I think a fold was the proper move unless Hero was convinced that his opponent was bluffing into two opponents with 10-8 (which was possible) or overvaluing a worse made hand (which was improbable).

Hero called and lost to A 7.

After losing his entire stack, Hero became angry and started berating his opponent about his poor play. In reality, it was Hero's poor play that resulted in his being outdrawn. He almost surely could have gotten his opponent to fold by betting more aggressively earlier in the hand. Don’t be blind to your own mistakes.