I think that the best evidence for his success are the testimonials of his success by other traders of the same period. He had the respect of his fellow traders. I do not recall anyone of his period not showing some admiration for his work.
I personally do not pay much attention to his timing models. However, it is hard to argue with his advice on keeping data on the markets, understanding seasonality, trade in the direction of the trend and patiently wait for pullbacks to trade in the direction of the trend. In commodities, these suggestions work quite well.
http://www.market-analyst.com/articles/W.D._Gann_-_Market_Master
Charles
I personally do not pay much attention to his timing models. However, it is hard to argue with his advice on keeping data on the markets, understanding seasonality, trade in the direction of the trend and patiently wait for pullbacks to trade in the direction of the trend. In commodities, these suggestions work quite well.
http://www.market-analyst.com/articles/W.D._Gann_-_Market_Master
Charles