Opening from under the gun
When the action folds to you under the gun, the starting chart opens 16% of hands in a 6-max cash game with 100 big blinds.
Why this range
Five players act after you, and any of them can wake up with a strong hand. The opening range is the tightest at the table: pairs, strong aces and the best suited broadway hands.
When you open here, your range is strong, and observant opponents know it. That gives your continuation bets more credit on high-card boards.
How wide to open
The chart raises 16% of hands and folds the rest. There is no calling when everyone before you has folded: if a hand is good enough to play, it is good enough to raise.
The chart raises to 2.5 big blinds. Use the same size with every hand you open, so that the size says nothing about your cards.
About the numbers
The figures come from the rule-of-thumb charts on this site, not from a solver. They are a sound default to learn first. In the trainer you can edit every chart and train on the hands at the edge of the range.
The charts
Terms in this guide
Practise it
Reading is the easy part. Play the hand of the day, or deal ten hands in the trainer and see which of these decisions cost you the most.