Quoted from Frax:If you're going to half-ass it at least half-ass it right.
Do the opposing corner holes and use TWO bolts so you don't tear off one hinge side.
Oh wait, but then you might as well take the extra 30 seconds to put the other two in as well, because you've already spent 15 seconds doing the second one.
One bolt in a WPC-style game is plenty.
I've never, in history, ever, in 16 years in this hobby, heard of a latched head failing and coming "crashing down" as some have mentioned, even without head bolts. I've certainly never heard of a head being "torn off one hinge side." How rough are you guys with your games?! I don't think I could cause that kind of damage if I tried. Maybe if I were to hang the game upside down like a bat, and then perform some kind of cirque du soleii style acrobatics on the game with the help of hydraulics, at a fast pace, with insanely high g-force lateral movements?
Even anecdotally I've never heard of a latched head coming down. It just doesn't happen, and plenty of people don't bother with head bolts. Even WITHOUT a latch OR bolts it probably wouldn't happen - the way a WPC is built and the weight distributed, it doesn't want to do that. Early System 11s would be a different story.
A boring and uninteresting story...
I once bought a Fireaball EM from a guy on Long Island. he'd had the game for decades. I'm breaking this thing down, take the back door off, and....there are NO head bolts, no anything else connecting the head to the body except for the jones plug connectors. This thing had been sitting like that since the early 80s. Yikes!