Methods (as discussed in his book 'Pit Bull'):
-caught the parabolic move in gold in the late 70s/80s, made a ton of money trading options on ASA (from his book).
-eventually migrated and traded the S&P 500 contract when it first came out, primarily scalping in and out during the day.
-said in a more recent interview that he moved to trading oil futures, in the late 2000s, and was now selling premium due to the size of his bankroll.
I agree with you about Marty Schwartz but this kind of stuff is why their results are so disheartening.
Most of the "supertraders" made their money when money was literally being handed to anyone with a pulse - the options and futures market of 197x to ~198x. It's easy to stay a supertrader after you double your account over and over again in the easiest market to trade in the last 50 years.
I doubt we will see modern supertraders of the scale we have seen in the past. The markets are far more efficient than they were and its nearly impossible to achieve the scale of return these guys did because there aren't many "parabolic" moves anymore in highly leveraged instruments.
Ed Thorp comes to mind.
Ed Thorpe is exactly the same as Marty Schwartz. A pretty talented guy that found a MASSIVE edge in a super inefficient market and exploited the absolute shit out of it. We won't find any Ed Thorpes (nobodies who suddenly became someone by exploiting a non-trivial mathematical fault in pricing) anymore. He basically started the quant craze. Anyone capable of that is working for a hedge fund or BB.