The experiment
Over the Spring 2009 semester two Berkeley undergraduates, Priscilla Ku and Janet Larwood, undertook to do the required 40,000 tosses. After preliminary experimentation with practical issues, there was formulated a specific protocol, described in detail below. Cutting to the chase, here is the complete data-set as a .xlsx spreadsheet (see sheet 2). This constitutes a potentially interesting data-set in many ways -- one could compare numerous theoretical predictions about pure randomness (lengths of runs, for instance) with this empirical data. For the specific question of dynamical bias, the relevant data can be stated very concisely
of 20,000 Heads-up tosses (tossed by Janet) 10231 landed Heads
of 20,000 Tails-up tosses (tossed by Priscilla) 10014 landed Tails