While I don't have a good excuse like ZCM82, I can truthfully say my last unsupported shot on a deer was maybe 18 years ago. You can call it laziness, but I just lost my taste for goat rodeos. Close to half of my shots have been off a bag. I keep them in all my ground blinds. My tower blind and my treestands all have shooting rails covered in pipe insulation.
I took my buck last November with a shot off the back of my ladder stand. I braced my Savage 99 on the tree and nailed the deer at 80 yards.
I still have plenty of offhand opportunities during Squirrel and Turkey Seasons. For deer, I have a little over 2 weeks to fill the freezer and I ain't dickin' around.
The first deer I ever shot was an offhand goat rodeo... never again. I got it, but it was really, really ugly. I've learned my limitations, and aside from off a bench where I have all the time in the world, would consider myself a fairly poor shot overall. There's a lot of years I don't tag a deer because I'd rather pass on a shot than take a bad one, and there isn't an overabundance of deer where I hunt.
Like you, I have rails all around to shoot off of from my stands, and I try to keep my shots inside 100 yards or so. Maybe 150 if it's dead calm and the quarry is just standing like a statue to where I have a lot of time to shoot.
About the only offhand shooting I do is at rabbits at very short range since they're about as tough as pudding and basically any hit anchors them, or birds with a shotgun. I still carry shooting sticks or a monopod for rabbit hunting, and use them if I have time.
