To reconcile the discrepancy between the efficient market hypothesis and grain marketing recommendations by advisory services and extension programs, simulated prices from an efficient market are used to compare performance of marketing practices over the long run and in individual 40-year periods. We find that an efficient market can generate diverse price behavior within finite samples, allowing for strategies that are inferior on average to perform relatively better, as frequently as half of the time in an average 40-year lifetime. Lifetime returns of strategies show considerable overlap, suggesting extremely low confidence in recommendations made based on short samples.