Will Big Ben live up to his role as favorite?
After receiving a bye in the first round, top seed Ben Shelton kicks off the tournament. The world No. 5 is the favorite to win the 2026 ATP Stuttgart, but he faces a tough test right in his first match. After all, when betting on Ben Shelton vs. Marcos Giron, it must be taken into account that while Big Ben leads his compatriot 2-1 in head-to-head matches, the set count between the two stands at 4-4.
This American showdown took place just a month ago—curiously enough, also in Germany, specifically on the Elbe River at the Hamburg Open. Here, too, Big Ben prevailed by a narrow margin of 2-1 (6-3, 4-6, and 7-6). Accordingly, the odds for Ben Shelton vs. Marcos Giron suggest that this matchup will once again go the full distance of three sets.
An interesting question is to what extent the grass will be an advantage for the favored Ben Shelton. Generally speaking, “The Mountain” has the better serve, averaging 10.67 aces per match in 2026, and he is particularly skilled at serve-and-volley, a style that shines especially well on grass. On the other hand, Marcos Giron—who is better known for his return game—made a positive impression in the first round with a straight-sets 2-0 victory over the strong, consistent Roberto Bautista Agut, hitting 15 aces. The Californian, currently ranked 88th in the ATP world rankings, can therefore be expected to win at least one set.
In addition, Marcos Giron has the advantage of having already kicked off the grass-court season on Tuesday, while Ben Shelton hasn’t played a match since his disappointing second-round exit at the French Open and is now facing his first ranked singles match on grass since the summer of 2025. The potential adjustment period also supports the prediction that the Californian will win by more than 0.5 sets. Nevertheless, a victory for the top-seeded world No. 5 remains likely.
Ben Shelton – Marcos Giron Head-to-Head Record
Head to Head: 2:1
The two compatriots have faced each other three times in ranked singles matches on the ATP Tour so far, and Ben Shelton currently leads the head-to-head record 2:1.
After Marcos Giron won their very first match in Delray Beach in straight sets, 2-0, Big Ben went on to record two close 2-1 victories in a row against the Californian, whom he beat just a month ago in Germany. At the ATP Hamburg tournament on clay, the final score was 6-3, 4-6, and 7-6.
Now the two Americans will face off on grass for the first time.
Ben Shelton – Marcos Giron Prediction
On paper, there is every reason to believe that the player from Atlanta, Georgia, currently ranked fifth in the ATP world rankings, will live up to his role as favorite and win his first match at the 2026 BOSS Open. But it won’t be easy for Big Ben, whose opponent has already had time to acclimate at the Tennis Club Weissenhof, defeating Roberto Bautista Agut 2-0 in the first round and firing an impressive 15 aces in the process.
The Californian is likely to make life just as difficult for his top-seeded compatriot this time around, especially since Marcos Giron has won at least one set in all three of his previous matches against “The Mountain.”
We therefore expect this all-American matchup—which last took place just a month ago in Hamburg—to go the full three sets again. For over 2.5 sets, Interwetten is offering odds of 2.30 on Ben Shelton vs. Marcos Giron, which we’re betting on with three out of ten units.
