# How to use (or not use) Chen formula valuation in different scenarios?

Let's say that using Chen's formula and a bit of practice one calculates the score of his hand preflop very quickly when playing. The problem is that I'm sure you shouldn't act in the same way in different scenarios. So, would use a variation or adjustment of the formula for the following situations or perhaps simply change the threshold for folding, calling and raising in each position for each of the scenarios?

Some sample scenarios:

• 10 players at the table
• 3 players at the table
• short stack
• tournament
• cash game
• antes vs no antes
• limit vs no limit
• blind, stack ratio etc

At the very least I would like to know what the standard scenarios in which is safe to use Chen formula are and outside of that which other scenarios can I typically encounter in which I have to do something else.

First, be aware that the Chen formula can only be a very rough guideline as to whether to play your hand. It is not the be-all and end-all. Also note that Bill Chen himself said that the formula can only help inform you what hands to play. It can't tell you when you should check, call, raise etc. That said, hands that score well on the Chen formula are generally much more playable than hands that score badly, and there is clearly something to the formula.

The guidelines at Simply Holdem suggest that you can use the following criteria for raising and calling, depending on your position -

Early Position

• Raise if 9 or higher
• Call if 8 or higher, otherwise fold

Middle Position

• Raise if 9 or higher
• Call if 7 or higher, otherwise fold

Late Position

• Raise if 9 or higher
• Call if 6 or higher, otherwise fold

Those certainly aren't hard and fast rules, but they might be helpful for a beginner. In generaly, we can make the following statements about how you should player tighter/looser depending on various other factors.

## Position

You need a much stronger hand to call or raise in early position than you do in late position. In late position you can afford to play looser, since you will retain the position advantage on subsequent rounds.

## Raise in front of you

If there has been a raise in front of you, you need a much stronger hand to call than if there has been no raise.

## Number of callers

In general, you should have a stronger hand to call or raise when there have been many callers in front of you (because of the danger of flush and straight draws). The exception is when you hold a drawing hand yourself (eg suited connectors, or a small or medium pair). In that case you may want to call even if your hand isn't that strong at the moment, because of the implied odds when you make your hand.

## Short stack

There is some pressure to play looser than usual if you are short stacked, since you don't want to waste your stack paying the blinds while you wait for a good hand.

## Antes / no antes

The larger the antes relative to the typical bet, the looser you should play. This is because all that ante money in the pot is massively improving your pot odds.

## Limit / no limit

For beginners, I'd advise playing tighter in a no limit game than in limit, because it's easy to lose control of the game to a better player and you're prone to throwing good money after bad.

## Number of players

With few players (3-6) you should player looser, since there is less chance of another player having a strong hand, and your share of the blinds has increased, so waiting out rounds to get a great hand is expensive.

• Thanks. After I wrote my question I found out that this formula serves as a way to approximate Helmuth's playable hands so one doesn't need to remember them. It is not necessarily a valuation formula per se that can be adapted to different scenarios, as you explain in your first paragraph in other words. So the point of my question was more or less moot.
– DPM
Commented Mar 18, 2014 at 17:07