It was an exciting and emotional weekend for a bowler at Sheffield Lanes in Aliquippa, Beaver County. The bowling alley shared a video of Stephen Kosela throwing the final strike of his perfect 900 series. Watch the exciting moment in the video player above. This happened during the Beaver Valley USBC Association Tournament. The owner said this is only the 38th time that a sanctioned 900 series has been thrown in the country.