The ATP grass season opens this week, and the BOSS Open in Stuttgart has drawn an unusually strong field for a 250-level event. Four of the eight seeds sit inside the top 12: top seed Ben Shelton, defending champion Taylor Fritz, Alexander Bublik and Jiri Lehecka. The top half is built around Shelton and Lehecka, while the bottom half belongs to Fritz, back to defend the title he won over Alexander Zverev last year, and Halle finalist Bublik.
Shelton comes back to German lucky soil
Top seed Ben Shelton arrives off a strange clay swing. He won the last tournament played on German soil, the Munich 500, his first clay title outside the Americas, then won little else on the surface, losing his opener in Madrid and Rome and falling in the second round at Roland Garros to Raphael Collignon. Grass has treated him better lately: he reached the Stuttgart semifinals last year before losing to Zverev, then the Wimbledon quarterfinals where Jannik Sinner stopped him. His career grass record is still modest at 12-11, so this remains a surface he is building. He has a first-round bye and opens against Roberto Bautista Agut or Marcos Giron. Bautista Agut is the most experienced grass player in the field with 55 main-tour wins on the surface, more than anyone else here, even if his 2026 has been thin at 4-11 on the main tour.
The same quarter holds eighth seed Corentin Moutet, whose season has been poor at 6-12 on the main tour but whose grass form tells a different story: 9-4 over the last 52 weeks, a Mallorca final last June and a win over Fritz in London. His opener is one of the more watchable first rounds, against wild card Nick Kyrgios, who returns with a 0-1 record this season but a strong 33-18 career mark on grass. Quentin Halys and qualifier Sho Shimabukuro complete this quarter. Shimabukuro reached the Birmingham Challenger quarterfinals this week and the Ilkley Challenger quarterfinals last year, recent grass form that comes at Challenger level rather than on the main tour.
Fourth seed Jiri Lehecka anchors the other top-half quarter and brings the best recent grass results of anyone in the draw: a Stuttgart quarterfinal and a run to the London final last season, where he beat Alex de Minaur and Jack Draper before losing to Carlos Alcaraz, along with a heavy serve that averaged 10.6 aces per match on the surface. He has a bye and opens against German wild card Diego Dedura or James Duckworth. Sixth seed Frances Tiafoe sits in the same quarter and opens against home player Daniel Altmaier; Tiafoe owns 24 career main-tour grass wins but has played just three grass matches in the last year, winning one.
Across the top half, the grass profiles from the past year point to Lehecka and Shelton. Lehecka stands out on the power index and dominance ratio with a strong serving line, while Shelton's serve and overall index also rate well, both built more on holding than on returning. Bautista Agut's numbers reflect his discipline, with very few double faults per game.
Fritz defends as Bublik anchors the bottom half
Defending champion Taylor Fritz is the second seed and the form grass player on paper, with a 13-2 record over the last 52 weeks that includes this title over Zverev, the Eastbourne 500 crown and a Wimbledon quarterfinal. The caution is everything that has happened since: a two-month injury layoff, a flat return in Geneva and a first-round loss to qualifier Nishesh Basavareddy at Roland Garros, where he failed to convert from two sets up. He has a bye and opens against qualifier Pierre-Hugues Herbert or Martin Landaluce. Seventh seed Alejandro Davidovich Fokina shares his quarter, opening against Mattia Bellucci, and brings a tidy 5-2 grass record over the past year.
Third seed Alexander Bublik headlines the other bottom-half quarter and carries one of the better grass stories of last season, winning Halle by beating Sinner and Daniil Medvedev before a first-round Wimbledon exit to Jaume Munar undercut the run. He is 18-12 in 2026 and has a bye, opening against home favourite Jan-Lennard Struff or qualifier Alexis Galarneau. Fifth seed Tommy Paul completes the quarter and is the field's strongest performer this year at 26-11 with a Hamburg final, though grass has been his weakest surface lately at 1-2 over the last 52 weeks. He opens against big-serving Giovanni Mpetshi Perricard, whose own grass form has dipped to 1-3. Fabian Marozsan and qualifier Gauthier Onclin fill out the section, with Onclin's grass figures lifted by his qualifying run rather than main-tour results.
In the bottom half, Fritz's grass profile from the last 12 months is the most rounded in the field, leading on the power index and match efficiency with strength across most categories. Bublik rates well on match efficiency and aces, again a serve-led profile, while Hanfmann's stronger marks come on return and break-point conversion. One pattern runs through the top names on both sides: break-point conversion is where even the better servers rate lowest.
