Thumb on top or below the safety? 1911

What are the advantages and disadvantages of riding your thumb on top of the safety? For Perry this year I decided that to keep my thumb below as I felt I would drive the gun left or right depending how much pressure i put on top of the safety but when i looked down the line of good shooters I notice they where riding on top. Normally I would ride on top on a two handed grip, what are your thoughts?

Comfort and consistency. For me, my thumb sits on top of the grip safety. It is a comfortable grip and I can easily repeat it. I don't apply a significant amount of pressure with my thumb, I apply pressure with my middle and ring finger on the front strap, driving the mainspring housing into the web of my hand.

Depending on your hands one method may work better than the other, I recommend trying both methods.

Pure personal preference. I know HMs that use either grip.

Just be consistent with your grip and don’t add/change pressure while your trigger finger moves.

I know quite a few Master and High Master shooters. Most comfortable position is best! Those that I know that have the thumb up usually have the thumb off the safety, some what off the grip and the frame including the safety especially if a Beaver-Tail grip safety is used. I personally like the thumb below the safety on the grip. If my memory is correct Adam grips the 1911 the same way, thumb below the safety and on the grip.