A look at the U.S. Open, the year's last Grand Slam tennis tournament:
Surface: Hard courts.
Site: USTA Billie Jean King National Tennis Center in New York.
Schedule: The 14-day tournament begins Monday. The women's singles final is Saturday, Sept. 10; the men's singles final is Sunday, Sept. 11.
New This Year: A $150 million retractable roof has been installed at Arthur Ashe Stadium, which will allow play when it rains.
2015 Men's Singles Champion: Novak Djokovic of Serbia.
2015 Women's Singles Champion: Flavia Pennetta of Italy.
Last Year: Serena Williams' bid for the first calendar-year Grand Slam since 1988 ended with a stunning loss to unseeded Roberta Vinci in the semifinals. Vinci then lost to Pennetta in the first all-Italian major final, 7-6 (4), 6-2. After winning her first Grand Slam trophy, Pennetta announced she would retire at the end of the season. Djokovic beat Roger Federer 6-4, 5-7, 6-4, 6-4 for his second U.S. Open title and 10th major championship overall.
Key Statistic I: 22 - Number of Grand Slam singles titles won by Williams, sharing the professional-era record with Steffi Graf. Williams can break their tie at Flushing Meadows. Only Margaret Court has won more, 24 - 11 as a professional, 13 as an amateur.
Key Statistic II: 186 - Number of consecutive weeks Williams will have spent at No. 1 by the end of the U.S. Open, equaling Graf's all-time WTA record. Depending on results in New York, Williams could be surpassed in the rankings after the tournament.
Who's Missing: Top names missing from this year's field include Roger Federer (letting left knee heal), Maria Sharapova (serving a doping suspension), Victoria Azarenka (pregnant), Tomas Berdych (appendicitis).
Prize Money: Total payout to players is a tournament-record $46.3 million, a $4 million increase from 2015. The men's and women's singles champions each receive $3.5 million, up from $3.3 million last year.