Senior Staff
David MacBurnie, USPTA
Founder of NETRESULTS Tennis, MacBurnie has been directing high end tennis operations beginning in 1982 at the Florida Yacht Club (Jacksonville, FL). In 2002 he began NETRESULTS and consulted with the Tennnis Programs of Harvard to revamp their curriculum and to inject a new dynamic style of instruction as our first client. NETRESULTS client list consists of; The Eastern Yacht Club (Marblehead, MA), Weston Recreation (Weston, MA), Brookline Recreation (Brookline, MA), the town of Palm Beach, FL (Seaview Park TC / Phipps Ocean Park TC) and our newest partner, Tampa Tennis at HCC in Tampa Bay, FL. Currently NETRESULTS Tennis provides services to over 6,700 families on the east coast.
He is a certified USPTA Professional 1 since 1986, a USA Tennis High Performance Coach and former top 10 nationally ranked player. MacBurnie played collegiate tennis for Rollins College (Winter Park, FL) winning All Sunshine State Conference honors twice. MacBurnie also was a USTA National Intersectional Team Champion (Florida) and ranked #1 in SC Men’s 30 Singles in “97” & “98”. In 2007 and 2009, David is a 5 time winner Men’s 45 Atlantic Coast Cup Team as well as the International Friendship Cup winning team representing New England at the #1 singles position. David captured the New England Men’s 50 Sectional singles championship in 2009 and 2010. In 2010, David was inducted into the Newburyport High School Hall of Fame as an All State/All League hockey player as well as a 2 time All League tennis champion and 4 year MVP at the #1 singles position for the Clippers, finishing with an individual record of 88-10.
Geoff Jagdfeld (Executive Director)
Geoffrey Jagdfeld epitomizes passion, expertise, and visionary leadership in racquet sports. With a Bachelor of Science in Exercise Physiology from Michigan State University, Geoffrey has built a career marked by innovation and impact. Geoffrey has held key roles in prestigious organizations such as the USPTA and USTA. As President of USPTA Eastern, his strategic leadership elevated the organization, driving initiatives that reshaped tennis education and engagement. At the USTA, he expanded junior tennis programs and fostered community relationships. His influence extends to club management, where as General Manager of New Canaan Racquet Club and HALO Fitness, he spearheaded initiatives that enhanced community engagement and boosted membership. As Director of Tennis at Solaris Sports Club, he introduced pioneering programs like USTA Jr. Team Tennis leagues, revitalizing tennis participation. Geoffrey’s contributions have been recognized with awards including the USPTA Eastern Industry Excellence Award and USTA Eastern Tennis Professional of the Year. His certifications from USPTA, PTR, and USTA underscore his commitment to professional mastery. Geoffrey Jagdfeld continues to inspire and innovate, shaping the future of racquet sports through strategic partnerships and player engagement initiatives.
Tommy Lay 
Originally from Cambodia, Tommy moved to the US to further his education. Along the way Tommy developed passion for tennis and fell in love with the game. During High School he played the USTA Circuit 18’s winning the USTA Mayors Cup Championship in 2000. Tommy played #2 at University of Massachusetts Boston for three years, competing on the USTA professional circuit for another two years.Tommy became a volunteer with Tenacity and the USTA 10 and under program in 2000, certified in 2001. Tommy became head tennis pro with Tenacity for Summer/School year programs for 8 years and Senior tennis pro at Harvard Tennis Academy for three years.Tommy has been with NETRESULTS serving as Director of Jr Developmental summer program and a senior staff professional throughout the year.Tommy enjoys working with all levels of juniors, specializing in the Developmental program with significant success. His passion as a teaching pro is to develop young players, instilling excitement his in his students in hopes of developing a champion player in the future. Tommy is excited to continue his relationship.
David Mulas (Senior Staff)
Introducing David Mulas Zelenskaya, a seasoned tennis professional with a passion for the game and a keen interest in the dynamic world of marketing. As an international student, David brings a unique perspective and a wealth of experiences to the tennis court and beyond. With a strong foundation in tennis, David has honed not only his skills on the court but also his leadership abilities. He was named team captain for the 2022-2023 regular season, where he led his team with dedication and determination, fostering a culture of excellence and teamwork. Now, as a tennis teaching professional with NETRESULTS, David is excited to share his love for the game and his expertise with aspiring players of all levels. His experience as a player and leader informs his approach to coaching, where he prioritizes not only skill development but also mentorship and personal growth. Join David in the exciting journey of tennis and marketing! Whether you’re looking to improve your game or enhance your marketing efforts, he’s here to guide and support you every step of the way. Let’s connect and embark on this thrilling adventure together!
Caleb Slotnick (Senior Staff)
Caleb is a valued member of the NETRESULTS team and has been an integral part of our coaching staff for over five years. A dedicated teaching professional, Caleb has made a lasting impact on the Brookline tennis community through his passion, consistency, and commitment to player development. Caleb’s love for tennis began early, playing with his family and continuing to grow throughout his college years, where he often hit the courts with friends as a fun and effective way to relieve stress. Today, Caleb brings that same joy and energy to every lesson, combining his enthusiasm for the game with a desire to help others improve and enjoy tennis as much as he does.
Rodrigo Araujo (Senior Staff)
Rodrigo’s passion for tennis began at age eleven when he started assisting his four uncles with lessons. With over a decade of coaching experience and a strong foundation built through family mentorship, he brings energy, dedication, and a thoughtful approach to every session. A recent graduate with a degree in Management, Rodrigo blends strategic insight with his love for the game to help players develop both on and off the court. His teaching style emphasizes fundamentals, fun, and continuous improvement—whether working with beginners or competitive athletes. Rodrigo is committed to growing as a coach and sharing his enthusiasm for tennis with every player he meets.
Will O’Brien (Senior Staff)
Will O’Brien is originally from Upstate New York, where he grew up playing competitive junior tournaments before continuing his career at Fairfield University. Over the past seven years, he has taught tennis in East Hampton and Saratoga Springs, working with players of all ages and skill levels. Now teaching part-time, Will brings both experience and enthusiasm to the court, with a passion for helping players improve and enjoy the game. Will recently got to the doubles semi finals of the Men’s Open Grass Court Championships that was hosted at the Tennis Hall of Fame.
Sujit Chepuri (Senior Staff)
Originally from Minnesota, Sujit Chepuri began his tennis journey as a competitive junior and standout high school player. He helped lead his team to multiple state championships while also achieving individual success in junior competition. His passion for the sport continued at Amherst College, where he competed as a four-year starter in both singles and doubles.Sujit’s coaching career began in high school, working summers at country clubs in the Twin Cities during 2019, 2020, and 2021. He quickly developed a love for teaching players of all ages, from children just learning the game to adults refining their skills. Since then, Sujit has guided the development of several competitive juniors and recently joined the coaching team at NetResults in Boston, where he continues to share his enthusiasm and knowledge for the game.
Ali Al-Sabbagh (Senior Staff)
Ali Al-Sabbagh brings a unique combination of teaching experience, community leadership, and passion for player development to the NETRESULTS coaching team. A Boston native, Ali has worked with youth and adults across the city for over a decade, including roles at Sportsmen’s Tennis Club and Edu Sports, where he created curriculum-based lesson plans and led summer camp programs for Boston Public Schools students. Ali’s teaching approach emphasizes patience, structure, and clear communication—skills he honed both on the court and in the classroom as a substitute teacher with Boston Public Schools. His focus on skill progression, sportsmanship, and creating a fun, supportive learning environment helps players of all levels build confidence and consistency. In addition to his tennis background, Ali has served in community-based roles promoting education, inclusion, and volunteerism, both locally and abroad. He holds a Bachelor of Liberal Arts in Africana Studies from the University of Massachusetts Boston. When he’s not coaching, Ali enjoys mentoring young people, volunteering, and staying active in Boston’s recreational and educational communities.