The "semi-bluff" is one of the most useful, risky, exciting, and underused tools in poker. Players who can use the semi-bluff effectively will wreak havoc on their opponents' chipstacks and see higher profits than those who don't utilize this effective tool.

A semi-bluff is different than a standard bluff. A standard bluff is a bet to get your opponent to fold because you basically have no chance of winning the hand at the showdown. A semi-bluff is when a player takes the lead in betting while on a draw.

There are various ways that a player can take the lead in the betting. One way is to be the first player to fire a bet into the pot. Another way is to raise a player who has already bet into the pot. The riskiest ways are to re-raise a player who has already raised the original bettor, or to check raise a bettor.

To understand when to semi-bluff, you must understand the different types of drawing hands and your odds of completing those draws. By fully understanding your drawing odds, you can use the semi-bluff to create favorable pot odds for yourself.

The two main categories of draws are primary draws and premium draws. Primary draws include open-ended straight draws and flush draws. Premium draws include open-ended straight flush draws, a primary draw with 2 overcards (when your opponent has a lower pair than you would have if you hit one of your over cards), or a primary draw with a pair and an overcard.

When it comes to semi-bluffing, the better your draw, the more you can afford to bet on a semi-bluff and still give yourself favorable pot odds. Also, the higher risks you take with semi-bluffing, the larger the pots that you win will be. The drawback to this however, is that if your bets are consistently and significantly larger than your drawing odds, you are increasing the likelihood of losing money in the long run.

Not only can a few well-timed semi-bluffs win you larger pots, but they are also effective in taking down smaller pots, the same way as a standard bluff or a continuation bet.

Another use for the semi-bluff is to buy a free look at the river. Suppose you are on the button with 9 10 of diamonds, and the board comes down 7 8 K with 2 diamonds. Your opponent, who has you beat with K J, fires off a bet. This is a perfect opportunity for a semi-bluff, so you raise. In this situation, your opponent may just fold, maybe putting you on AK. Even if he doesn't fold, he'll usually be pretty skeptical of his Jack kicker and likely just make the call. If the turn doesn't improve his hand (which it won't roughly 90% of the time), he'll check to you, expecting you to bet again. If the turn didn't complete your straight or flush, you can now simply check and see a free river card!

Here are some tips for successful semi-bluffing:

• Give yourself favorable odds when semi-bluffing
  
• The better your drawing odds, the higher risks you can afford to take
  
• Save the riskiest maneuvers, such as re-raising and check raising for powerful draws.
  

As you should always do when playing poker, mix it up. Don't always semi-bluff or always semi-bluff the same way. Often you will encounter players who are likely to pay you off when you do hit a draw. In those instances, you can simply call with favorable odds and don't need to resort to the more expensive trickery devices.