Van Tharp wrote "THE" book on position sizing, in which he does an in-depth analysis (lots of tables, charts and statistics) of Martingale, anti-Martingale, Kelly criterion, optimal f, and many other types of position sizing algorithms (93 different ones, total). It's called "Van Tharp's DEFINITIVE GUIDE TO POSITION SIZING". It also covers essential information about mental errors, biases, fallacies, and costly mistakes to avoid. It's big (380 pages), and it's not cheap (around $150-200 US). He also has a two dvd set that covers the essential "meat" of the book, but of course leaves out much of the detail. I love the way his mind works (the contextual perspective that is relatively unattached to any specific content, which he got from his training in neuro-linguistic programming, and working with thousands of traders with vastly different beliefs and methodologies, plus he's a Ph.D. shrink), even though I might not personally agree with all of his beliefs, but in this specific area, I haven't yet seen anyone in or near his class. Just my two cents, and I could be wrong - it's happened before, and it probably will happen again - LOL! (trader humor, we all have losing trades, don't we?)
What's the bottom line? Just like practically all of the great traders profiled in the Market Wizards series say, "You've got to find what works for you". In my opinion, this applies equally to method, technique, time-frame, markets, psychology and position sizing. Position sizing in particular must be approached with an understanding of personal, individual risk tolerance and risk aversion, and account size and our own objectives are also vital considerations and unique elements of a successful total trading plan. For people who want a "just do this" answer, look elsewhere; for those who want a broad understanding within which to find themselves and meet their goals, you might just end up loving Van Tharp as much as I do.