I've had the weird circumstance of owning two guitars that had twisted necks: an Epiphone Les Paul I bought new and just used standard 10s with since I bought it, and a used 2008 Gibson Shred V, which came with a terrible setup with some telephone cable looking wound strings. This made me gunshy about string gauge and really got me into used balanced tension packs, but I know most people don't use balanced tension. My new guitar came with a 9 - 46 set, and I do like them, so I wonder, how common are twisted necks really, and what normally causes that phenomenon?