Here are my predictions for the men's quarterfinals at the 2019 U.S. Open Championships. I have also predicted the women's quarterfinals. Last year I predicted 3 of 4 men's quarterfinals correctly and 3 of 4 women's quarterfinals correctly.
Matteo Berretini (ITA)  vs Gael Monfils (FRA) . This is a first-time meeting between these players. Berretini is one of the breakout players of 2019, having already won two tour titles this year. The 23-year-old is listed at 6-foot-5 and 198 pounds while 32-year-old Monfils is "only" 6-foot-4 and 187 pounds. This is an incredibly important match for both players, as every major quarterfinal is. It's Berretini's first but Monfils' 9th. Oftentimes, the older player suffers in this situation with the knowledge of how rare these opportunities are but it can also happen that the younger player is overwhelmed by the occasion. This is basically a "call-em" match and that situation I go with the better athlete. Mad Professah's pick: Monfils.
Rafael Nadal (ESP)  vs Diego Schwartzman (ARG)