The applet shows 3200 successive coin tosses, presented in 8 rows of 400 tosses each. The height of the image is the number of heads minus the number of tails (the "winnings" of Henry who wins a dollar if heads comes up, but losses a dollar if tails comes up.) Because of space constraints, the rows may overlap if the cumulative wins or losses depart far from zero. (The eight rows are spaced 50 pixels apart, so a win of 25 on one row will touch a loss of 25 on the previous row.) Often wins or losses become so great that solid blocks of blue are formed.
Hit "Reload" or "Refresh Screen" on your browser to do a new series of 3200 coin tosses. Each series of 3200 coin tosses starts from a value of zero.