Hopefully there's little to no bias based on scheduling, but even if there was, publishing the statistics would only exacerbate the problem. Not only would PG

Hopefully there's little to no bias based on scheduling, but even if there was, publishing the statistics would only exacerbate the problem. Not only would PG et al be thinking about this while the interviewed people ("This doesn't really seem interesting, but is that just because they're the 18th pitch today?"), but it would also distract the startups, when all they should be focusing on showing YC how awesome they are. As far as I can tell, the people at YCombinator are extremely qualified to pick the best companies out of the group, and they generally do a pretty great job of it.