How to defend against big opening sizes? l Barry's Strategy Corner

How should we respond to bigger than x2 raises when we are the Big Blind?

Something I have wondered about now is answerable thanks to the new GTO Wizard preflop solving. We all know about defending the BB wide, but what about against a big opening size? 

Most GTO preflop sims assume a 2bb opening size, but what about when the raiser opens to 3bb instead?

Tighter, but more aggressive

In theory the opener should be tighter to warrant the bigger size preflop. In normal GTO world, this is what the BB does against a 2bb Button open, at 40bbs effective:

As you can see we continue over 95% of the time. There is a small amount of shoving, some raising with strong hands, and the bluffs are offsuit high card/low card hands, which don't play well but have a blocker.

This is the same spot when we force the Button to open to 3x instead:

The most crucial thing is we fold so much more. We fold 39% of the time, compared to less than 5% of the time. We were getting a very enticing price to close the action before, we are not any more. 

We also see much more raising, of which the predominant raise size has been shove. Although the Button is tighter, it is still a wide opening range overall. That extra chip in the pot has made shoving to take the pot down much more appealing. 

The quality of the bluffs is stronger too. We have folded most of the trashy hands which bluffed before, but now our bluffs are more weighted towards high suited hands. Hands like K7s which have a good blocker but also have outs when called. 

Of course this assumes the Button opens a GTO range at 3bbs. In practice the larger opening size is often either greed with a big hand, or "scared value" with hands the player wants to protect. But as a general rule, we need to be tighter overall against big opening sizes, but more aggressive with the hands we continue with.