Leon: Thanks for your comment. It's good to have one's presence acknowledged occasionally.
What I intended to say was that I do not allow any investment within my small "gambling" account to ever exceed 10% OF THAT ACCOUNT, not 10% of my total at-risk investments. You are quite right -- I would not today put 10% of my TOTAL investment capital in a single option or stock, although I did do so in the early days.