A direct reduction method/system, including: adding variable amounts of natural gas, hydrogen, and a carbon-free oxidizing gas to a feed gas stream upstream of a reformer; reforming the feed gas stream in the reformer to form a reformed gas stream, and delivering the reformed gas stream to a shaft furnace, where the reformed gas stream is used to reduce a metallic ore material to a direct reduced metallic material. The feed gas stream includes a top gas stream recycled from the shaft furnace. Optionally, the carbon-free oxidizing gas includes steam and the method further includes controlling a steam flow rate of the steam to maintain a maximum k-factor value of the feed gas stream of 0.74 or lower. Optionally, the variable amount of hydrogen is selected to replace 20-90% of the natural gas by fuel value. The variable amount of hydrogen is selected based upon an available supply of hydrogen.