Ax Rule
I first heard this from Phil Gordon. I don't know if he created the idea, but it does work.
| If you are short-stacked and ready to go all-in, count the number of players yet to act, and if that number is less than x, then it is ok to shove. If it is greater, than you are more likely to be dominated. |
Pretty simple, right? It gets a little more complicated.
XX Rule
Ok, this is another all-in rule but works with pairs.
| Take the number of pairs greater than yours, multiply by the number of players left to act, and divide by 2. This will give you the % chance someone has a higher pair. With that final number, subtract 10% for greater accuracy. |
Here's an example of this one since it's a little more complicated. You get 66 and the are 4 left to act.
So one-half of 8 pairs greater than yours equals 4, then multiply by the number of people left to act (4) and you get 16. Take off a tenth and you've got 14.4.
Again, 0.5%*8*4=16% , error correct -10% of that and get 14.4%
The real answer is 1-(1-0.0048*8)^4=14.5%
Turn/River Percentage
Ok, this one is really simple.
| After the flop, figure out how many outs you have left to make your hand. Multiply that times 4 for the percentage you'll hit that on the turn, and multiple your outs by 2 for the river. |
Of course, this doesn't guarantee a winning hand, just simply making your hand.
Conclusion
I love these little formulas because they're quick and easy. If you have one, please contribute it below (serious ones only please!).