That's a good one. We teach our runners to peek in at 1b to anticipate breaking ball in the dirt, or for a good pitch to run on for the few green light guys. Little bit tougher to get signs at 2b against a good team, at least.
We coach them to take 90 feet on any dirt ball read, at least that's the expectation. They may break hard a put on the brakes if needed, but if they don't get a good break because they weren't anticipating they're going to get an earful.