premise: American Sniper (book) is about a sniper with 170 officially confirmed kills.
hypothesis: American Sniper . The film follows the life of Kyle , who became the deadliest marksman in U.S. military history with 255 kills from four tours in the Iraq War , 160 of which were officially confirmed by the Department of Defense . American Sniper (book) . With 255 kills , 160 of them officially confirmed by the Pentagon , Kyle is the deadliest marksman in U.S. military history .