totallyirreverent.com

Quoted from SimplyHoldem.com:

The formula below was developed by Bill Chen, winner of 2 WSOP bracelets. He basically developed a mathematical formula to determine if a hand is playable based on giving the cards certain values.

Determine your highest card and score as follows: (only use your lower card for gap and suited analysis)

• Ace = 10 points
• King = 8 points
• Queen = 7 points
• Jack = 6 points
• 10 through 2 = half of face value (i.e. 10 = 5, 9 = 4.5)
• Pairs, multiply score by 2 (i.e. KK = 16), minimum score for a pair is 5 (so pairs of 2 through 4 get a 5 score)
• Suited cards, add two points to highest card score
• Connectors add 1 point (i.e. KQ)
• One gap, subtract 1 point (i.e. T8)
• Two gap, subtract 2 points (i.e. AJ)
• Three gap, subtract 4 points (i.e. J7)
• Four or more gap, subtract 5 points (i.e. A4)

Sample scores
AA = 20 points
98s = 7.5 points
K9s = 6 points

The information below is not strictly from the Chen formula as he believed the system only told you what to play, not when to come in for a raise. There are too many factors in determining when to raise, call or fold. The scores below can be used as a general rule of thumb.

Early Position

• Raise = Score is 9 or higher
• Call = Score is 8 or higher
• Fold = Score is lower than 8

Middle Position

• Raise = Score is 9 or higher
• Call = Score is 7 or higher
• Fold = Score is lower than 7

Late Position

• Raise = Score is 9 or higher
• Call = Score is 6 or higher
• Fold = Score is lower than 6