Complex sentence: The 1953 U.S. Open was the 53rd U.S. Open, held June 11--13 at Oakmont Country Club in Oakmont, Pennsylvania, a suburb northeast of Pittsburgh.
Split into simpler sentences: The 1953 U.S. Open was the 53rd U.S. Open. The golf tournament was held June 11--13,1953, at Oakmont Country Club in Oakmont, Pennsylvania, a suburb northeast of Pittsburgh.