Sarah claimed this bespoke scratching post off a free list and we've been planning to add a vertical element above for the cats to extend their climbing. First thought was shelf with a hole in it, then that evolved into a tree branch spanning the corner, inspired in part by Hundertwasser, an Austrian architect who planted trees in apartments. To bring the outside in, we cut a section off a felled birch out back. (We checked if birch is toxic for cats. It's not.) [Correction: it's actually Alder, also not bad for cats.]
I marked the nearest studs and measured the distances to the corner. 21 3/4" & 32 3/8"
Then I transferred the measurements to the plywood on the pool table.
I laid the branch down on the marks, orienting it the way it would be hung. (The vacuum came in handy to prop it up. Properly.)
(But it went easier when Sarah held it for the second cut.)
These are the screws I used. Sarah held the branch in place. I drilled pilot holes all the way through the drywall, which is a terrible thing to do to your bits. The advent of the impact driver really changed the fastener game. Chunky lag bolts used to be the norm, now long strong hexalobular "star" screws rule. One in each end sufficed, those T30's drove in deep and firm.
It was an instant success!