I'm having problems getting my brain to read the title of your post properly Shaun! You see, the German for jewel in a watch context is "Stein" (though "Rubin" is also used, you'll see "21 Rubine" etc on some German watches) and, as my brain knows the context of the post, it's trying to read it as jewel twice :s And "Jeff's Jewel Rule" is as bad, the alliteration and rhyme make it a mouthful...

But whatever we call it, it's a good rule of thumb. If you see number of jewels on a Heuer dial, walk. The same almost holds true for the shock protection as well. Unless it is one of the French-made chronos, a Heuer will not say "Incabloc" on the dial either.