"The Cockroach works exactly like the Small Road, except it skips two columns to the left of the current column in the Big Road. The Cockroach Pig starts after the first entry in the fourth column of the Big Road.
If the hand in question causes a new column in the Big Road then compare the first and fourth columns to the left of the new column in the Big Road. If they are the same in depth, then record a red circle in the Cockroach Pig. If they are not, then record a blue circle.
If the hand in question is the same outcome as the previous hand (skipping ties), then compare the cell three cells to the left of the newly created entry in the Big Road with the cell directly above that one. If these two cells are the same, whether both Player, both Banker, or both blank; then mark a red in the Cockroach Pig. Otherwise, mark a blue. " (text source: wizardofodds.com)