piston seizing?

[wornknobby]

i've heard of cases of peoples pistons seizing and not causing any cylinder damage. is this common? I was planning on buying top-end kits ahead of time so i can change the top-end before it seizes, but i don't want to change the top-end that is in it too soon as i could maybe get more hours out of it. is it common for a top-end to seize even if at high rpms and not have the piston shatter or have any cylinder damage? I thought it would be natural to change the top-end after you have used it for so long. since i only use it for woods riding it isn't under any extreme situations for long. so i can get a longer life out of mine compared to people who race. but as long as i ran say 32:1 could my rings wear beyond their limit and still not have my piston seize and just loose power. as if i could do this then i could just change the top-end every time i felt the bike had no power at all.