The Japanese success in sinking or damaging almost all the US Pacific Fleet's battleships at Pearl Harbor forced the Americans to base their tactics on the aircraft carrier (though they would possibly have developed such tactics anyway). The Americans quickly assembled a group of task forces, each based around a single carrier. Through a series of raids on Japanese-held islands, the American gradually grew more confident in their handling of aircraft carriers, learning that the right place for the task force commander was aboard a carrier, not one of the escorting cruisers, and developing tactics like having a single fighter direction officer for task forces operating in company. The four great carrier battles of 1942 – Coral Sea, Midway, Eastern Solomons and Santa Cruz – were all fought by aircraft without the ships on either side actually coming in sight of one another. The Japanese carriers were caught time and again by American aircraft with a light screen of cruisers and destroyers, contributing to the loss of six Japanese carriers in the four battles.