Split wood has much more surface area than unsplit wood. It also has surfaces that are not covered with bark. Therefore, it will dry faster than unsplit wood. The ultimate example of this is birch wood. Wood not only takes up less space when stacked, but it allows air to circulate around the wood.
Good ventilation is the most important factor in having dry wood.
It helps to dry the wood by speeding up evaporation. If you have the space, you might want to employ a trick used by old timers. They stacked their wood in long thin rows spaced apart, and at right angles to the prevailing winds to ensure good ventilation. Covering the wood and keeping it off the ground are important because these practices keep the wood away from moisture. Wood acts very much like a sponge.