And make the guessing more possible. Maybe pick each batch of four or five to be very different styles.If the 'guess the author' game gets played again, it should probably be attenuated somewhat. Having 18 snippets all at once is kind of too much, both from a management standpoint and a reading/guessing standpoint (if it's going to be a regular thing, anyway). Even at only 250-500 words each, when combined they'd be the equivalent of two or three Lit pages of content to sort through.
Releasing them in smaller batches, say four or five at a time once a week or so (or whenever enough have been submitted), might help to encourage wider participation.