At attacher can guess, and has a 1/16 probability to guess right, but they have only one chance to guess because if you guess wrong, the process terminates (if

At attacher can guess, and has a 1/16 probability to guess right, but they have only one chance to guess because if you guess wrong, the process terminates (if it's a user-process) or the kernel panics (if it's in the kernel), so in the next opportunity you'll have it will be a different tag to guess.