Quote from kinggyppo:
on a daily chart you could use 20 to 30% of a 10 period average true range for es spy etc. for an a level. Mav correct me if I am wrong. Also, you can set a wide or narrow A level based on your style and current market volatility. The A level is related to volatility.
http://www.dacharts.com/templates/descr/ACDmethod.htm
http://www.thelogicaltrader.net/FuturesMagMarkFisherprofile.pdf
http://amgallo.com/trading/amgACD.htm
http://www.clever-trading-strategies.com/primer_on_acd_method.html
Thanks for the resources you posted here King