US Open 2026: The Hidden Numbers That Will Decide Round Two

Rain washed away 14 first-round matches, but it couldn't erase a hidden number: Ben Shelton's 78% second-serve points won in the last three sets against Griekspoor. Meanwhile, Novak Djokovic exited in the opening round, leaving a void no prediction model ever accounted for. The 2026 US Open is becoming a massive data experiment, where once-invincible seeds are exposing their limits. Day 4 at Flushing Meadows will feature 14 remaining first-round matches and 32 second-round matches. Djokovic's absence, along with many top players struggling with injuries, creates a chaotic landscape. But in this chaos, data becomes clearer than ever. I've been watching these matches through an analyst's lens, and I see signals the scoreboard can't show. Young players are rising, while veterans battle age and injuries. This creates an environment where anyone can win, and data becomes the ultimate weapon. The match between Ben Shelton and Hubert Hurkacz is a clash of thunderous serves. Shelton, with his powerful serve, showed impressive recovery. He started slowly, then adjusted his return position, improving his second-serve win rate from 38% to 71%. Hurkacz, back in the top 50, has a quiet advantage: his win rate when opponents return weakly. Recent data shows Hurkacz wins 67% of points when he ends the point within 4 shots. Shelton, conversely, often extends rallies, which can be a double-edged sword against an opponent who excels at short points. I predict a five-set match, with Shelton winning due to superior stamina, but Hurkacz will make him sweat to the last drop. Shelton had 23 aces in the first round, while Hurkacz had 19, showing balance. Felix Auger-Aliassime faces Karen Khachanov, a match I believe is about hidden numbers. Auger-Aliassime had 17 aces in his opener, but his second-serve win rate was only 44%. He also converted just 3 of 10 break points, a worrying number. Khachanov, a 2026 US Open semifinalist, has experience and power. Interestingly, Khachanov wins 58% of points when opponents stand deep on return. He also has a great down-the-line backhand, creating pressure. Auger-Aliassime needs to improve his break point conversion, where he was 3/10 in the first round. I lean toward Khachanov in five sets, due to his consistency in clutch moments. Khachanov has won his last 5 five-set matches, while Auger-Aliassime has won only 2. Carlos Alcaraz, the defending champion, is regaining his feel after injury. He beat Roman Safiullin impressively, with 15 aces and 80% first-serve points won. But Jaime Faria, who just survived a five-set battle against Jenson Brooksby, could be a tougher test. Data shows Alcaraz wins only 52% of points when opponents serve to the center, a weakness Faria can exploit. Faria won 68% of first-serve points against Brooksby, and he moves well. However, Alcaraz can adjust tactics quickly, and I believe he'll win in five sets, but not easily. Alcaraz needs to improve his return win rate, currently at 33% in the first round. Gael Monfils, at 40, is having an emotional farewell season. He played spectacularly against Adolfo Daniel Vallejos Alvarez, with artistic one-handed backhands. But Learner Tien, the 14th seed, is a young, durable opponent. Tien beat Nuno Borges in straight sets, showing focus. Monfils can create magic moments, but distance data shows Tien moves 12% more than Monfils in recent matches. Tien also has a 56% second-serve win rate, above the tournament average. I predict Tien wins in five sets, thanks to freshness and endurance. Monfils might win the first set, but stamina will be an issue. Many will say Monfils' experience or Shelton's power is decisive. But I see the opposite: in five-set matches, players with high "quick point ending" rates win more often. Hurkacz and Khachanov belong to this group, and they can exploit opponents' fatigue. This doesn't mean they'll win, but it shows that point duration data can matter more than aces. Also, Djokovic's early exit could relax other players, but also make them complacent. I've seen many such cases in my analysis career. Weather in New York is always unpredictable. Rain disrupted the schedule, which could affect players who have to play multiple matches in a row. Players who adapt quickly to court conditions will have an advantage. Also, Djokovic's absence opens opportunities for young players, but also creates invisible pressure. They must prove they deserve their spot, and data will be a reliable companion. In today's era, players all have data analysis teams. They track every shot, every step, every decision. But the key isn't having data; it's how they use it. Shelton adjusted his return position based on data about Griekspoor's serve direction. Auger-Aliassime needs to do the same against Khachanov. That's the difference between winner and loser. This second round will test my prediction models. I once burned my model with Croatia in 2026, and I learned that data is never absolute. But if one thing is certain, it's that players who know how to read match data will have an advantage. Watch second-serve win rates and break point conversion – those are the hidden numbers that will decide their fate. Can Shelton maintain consistency? Can Alcaraz regain form? We'll see.