Ian Strimbeck of Rune Nation LLC talks about the thumb pectoral index, which was originally developed by Craig Douglas of ShivWorks.
We see a lot of shooters firing from the the hip and/or rib cage with the gun flat when practicing shooting from retention. While this method can be useful, it doesn't address the issue of rounds passing through the target and a safer angle to engage from.
Practice at your own risk, and follow all laws in accordance with concealed carry and having to potentially use a weapon in self defense. This information is intended for firearms professionals who work within the scope of the law, and is not intended to be used out of context.