The stock market and the gridiron and the battlefield aren't as tidy as the chessboard, but in all of them, a single, simple rule holds true: make good decisions and you'll succeed; make bad ones and you'll fail.
Whenever a man can get hold of numbers, they are invaluable: if correct, they assist in informing his own mind, but they are still more useful in deluding the minds of others. Numbers are the masters of the weak, but the slaves of the strong.