Controlling the Barrels in Donkey Kong
donhodges.com
donhodges.com
I think I just added more vanilla barrels, more wild barrels and more X-velocity jinks to increase the difficulty. I was totally guessing just based on a few weeks of playing the game intensively.
When is it advantageous to force a barrel drop?
More advanced players will use barrel control to group 2 or 3 barrels together so they can jump over them for more points.
Check out The King of Kong: A Fistful of Quarters to learn more about Donkey Kong and classic arcade games in general.
http://en.wikipedia.org/wiki/The_King_of_Kong:_A_Fistful_of_...