BE AWARE of the Scam by Frantz G Glasz -- This Is My Real Experience Hear me out you'll see why he's extremely evil, cruel, manipulative, someone you want to avoid at all cost. I purchased 10 private 1:1 tennis lessons from Frantz G Glasz, but only completed 4 due to extremely poor quality, unsafe instruction, unprofessional behavior, and his ongoing refusal to issue any refund despite multiple attempts to resolve the situation. 1. Suspicious payment methods & refusal to issue receipts Between Oct 2022 - Dec 2022, Frantz required the entire $1,000 payment upfront, and cash-only. He refused Venmo, Zelle, or any digital payment, and refused to provide a proper receipt. I had to insist multiple times just to get a basic text message confirming payment -- the entire arrangement already felt questionable and unprofessional. 2. Unsafe instruction that caused an injury In my 2nd lesson (10/22/22), due to his lack of guidance and proper coaching, I suffered a wrist injury that took 2 months to heal. For a total beginner, his careless approach was unsafe, and he showed no concern or accountability. Across all lessons, he put in minimal effort, offered almost no true instruction, and showed no intention of actually teaching. 3. Lied about court reservations & wasted my time During my 4th lesson (12/2/22), he claimed the court was reserved, but it was clearly not. When I said I needed to return to work since no court was available, he insisted he had "other courts reserved" and told me to get in his car. I trusted him -- and he drove me around San Francisco for nearly an hour with no reservations anywhere. The lesson never happened, and he left me far from the original meeting point afterward. He lied repeatedly, wasted my time, and acted irresponsibly. 4. Unreachable afterward & defensive when I raised concerns After that day, I tried to schedule my next lesson, but he ignored my messages. When I expressed concerns about the poor quality of instruction, he immediately became defensive, rude, and dismissive, showing zero interest in understanding or improving. His polite-sounding public review responses are performative -- in private he behaved very differently. 5. Inappropriate personal comments during lessons Throughout my lessons, he asked inappropriate personal questions (e.g., whether I was single) and talked about his own dating life -- which was unprofessional and made me uncomfortable. 6. Refused to refund unused lessons When I requested a refund for the remaining 6 lessons (lessons 5-10), he refused to refund even the 5th lesson, which had not happened yet. He took advantage of my trust and acted with dishonesty and zero professionalism. 7. Denied ever teaching me in public after I posted my review Over the past 3 years, I have attempted to contact him for a refund, especially given the unsafe coaching, injury, and unprofessional conduct. He never responded. After I posted an honest review about my experience, he publicly denied ever teaching me, which is simply false. This appears to be an attempt to protect his image rather than address legitimate concerns. Bottom line I trusted him because of his 5-star reviews, but my real experience was unsafe, manipulative, dishonest, and far below what was advertised. This whole process has caused me an unbearable amount of pain and has had a deep, lasting impact on my mental health. I was left with a very clear impression of his character: someone driven by greed, ego, and self-interest, with no regard for the impact he has on others. His actions felt deeply selfish, cruel, and manipulative. Avoid him. He took my money, provided unsafe and unprofessional lessons, and refused any accountability or refund. read more

We had tried a handful of tennis instructors in SF through various tennis sites that link you to local pros, as well as group lessons through parks and rec, and none of them come anywhere close to being even half as good as working with Frantz has been. He did in one lesson more than any of the other instructors could do in months of lessons, he's a fantastic teacher and manages to keep things upbeat and fun. I do not think you could find a better instructor anywhere in the Bay Area. Frantz is able to help improve your game no matter what level you are at, it doesn't matter if you are an absolute beginner or an experienced player who has been playing competitively for years, with his coaching you will see results. read more

Caltennis checks all my boxes: Skill development, well-paced clinics and private lessons, not too much talk-talk, hit alot of balls, get a good workout. And for a plus, you can get lessons in French. read more

Enrolled my son in CAL Tennis and he's having so much fun and learning a lot. Coach Frank keeps it stimulating for kids while teaching the fundamentals of tennis. He also emphasizes to kids be responsible & clean up after themselves (they need to pickup the balls at the end of the lesson) but does it in a way where my son has fun doing it. My son gets a lot of exercise, is getting better at tennis, and having fun while doing it. Definitely recommend this to other parents. read more

My 13 year old son has been training with Frantz for the last 3 months and the results have been fantastic. His approach to teaching the fundamentals and philosophy of tennis have had a direct impact on my son's ability to improve his game while sparking a deeper appreciation for the game. We'll be continuing to work with Frantz for the foreseeable future. read more

Coach Frantz is the best! I've had lessons on and off since I was a kid and this is the most I've learned and the most fun I have had! Highly recommend. read more

Frantz makes learning tennis fun! Super engaging classes that make 90 minutes fly by. I love the private lessons to learn new techniques and have some controlled structure and the group lessons to practice outside of a controlled space. Would highly recommend CAL tennis to anyone who's interested in taking up tennis. read more

CAL Tennis is a great organization! I got to know Frantz as a coach and he's the best! I highly recommend taking classes with him

I had a very negative experience with this facility. Initially I was supposed to take private lessons with Frantz, and I paid for the class, but I was never able to schedule the lesson nor to get a refund. I wasn't able to reach Frantz or anyone from Cal tennis. It's been months and they simply just don't care, and this feels like such a scam! read more

Frantz is a great teacher and makes the clinics fun and dynamic with a combination of drills and games. I look forward to the class every Saturday to meet new friends and hone my tennis skills. I'm really glad I found this this tennis community! read more

I've worked for Frantz for almost two years now, and am impressed not only with the organizational structure of the clinics/lessons offered, but also the expectations he has of coaches. There is a clear line of communication and follow through to ensure players are receiving the best experience possible. read more

After trying a few different coaches, I am sticking with this one. I enjoy the group classes and the teaching style where you can both learn and play a little bit. Franz is very knowledgable and plus he's a fun instructor! read more

I've been attending clinics with Frantz since late September and absolutely love them. We're usually an intermediate beginner group, and Frantz does a great job of covering the basics and giving us feedback throughout the clinic. Plus he makes the clinics so much fun. My skill level has continued to improve and I always look forward to training with Frantz! read more

Frantz is an excellent instructor who has years of experience. He will teach proper form and fundamentals. The clinics are not only informative but also a lot of fun. Highly recommend. read more

I've been looking to get back in the game, and loved the intermedia clinic! We were all evenly matched around 3.0-3.5 so it was a lot of fun. This is a perfect combination of playtime and instructions. read more

I've been working with Frantz for six months and have seen major improvements in my game! His clinics are fast paced and a great way to learn and meet people at the same level. He keeps it interesting, fun, and competitive. read more

Frantz is a wonderful coach. I've been taking lessons with him for 10 years and he helped me restart after many years away from the game. His private lessons helped me move from a 3.0 to a 3.5 level within a year. His clinics are fun and bring a great crowd of like-minded players. Frantz is passionate about tennis and his enthusiasm is contagious. I couldn't recommend Coach Frantz highly enough! read more

Great coach. Private lessons helped me a lot to progress fast. The clinics are very fun and Frantz always try to make sure that the exercise are adapted to the size of the group. read more

Franz runs a fun drill for intermediate players. He provides time to warm up, play out points with certain scenarios and adjusts depending on the number of players. It's hard to find a good tennis situation in SF and Franz is a great option. read more

Frantz is a great tennis coach! His clinics are extremely fun and are a great way to meet people while also working on technique and skill. He offers a range of services for all skill levels, and structures his drills in a way that everyone can benefit and learn. Taking lessons with him are a highlight of my week and I feel my tennis has improved greatly with his guidance. 10/10 recommend! read more

Frantz is very dedicated to what he does. I saw him at various occasions teaching kids and they all had a blast! He makes it so fun on the court! Great coach! read more

I played tennis recreationally in high school and as an adult, I was looking for lessons to rekindle my muscle memory. Picking up the racquet with Frantz I am experiencing tennis and what I am capable of from a new dimension. I have been taking private lessons with Frantz for 12 weeks and I look forward to class fog or shine because I always leave class feeling like I have learned something new, whether it's refining a technique or learning a new one. Frantz does a great job of breaking down different techniques, step-by-step, and when it all comes together in the final step it feels amazing what you can accomplish. read more

I searched for a while to find a drop-in clinic and am thrilled I found Frantz. His clinics include a good mix of cardio and hitting, with fun drills every week. Highly recommend coach Frantz! read more

Started taking private lessons and clinics with Frantz at my friend's recommendation, and have been really amazed by how much I've improved and how much fun I'm having. Frantz is a great coach and manages to give very personalized tips even in a group clinic setting. He also does an awesome job of matching people to the right level clinic and I've met a lot of great folks along the way. Highly recommend! read more

We feel fortunate to have happened upon Frantz. He's offered strong guidance every step of the way on our 9 yr old daughter's tennis journey. What stands out is his candid and personalized approach to assessing one's unique age appropriate needs to develop in the sport. He gives above and beyond what you'd expect. Attention and passion is exceptional. We leave every class feeling motivated and eager to put our new technique into practice. He will show you not just the mechanics of tennis, but also to see tennis as a way of being and thinking--and it's that higher plane that makes tennis so alluring. Thanks Frantz! read more

Awesome clinics with friendly players. Multiple levels supported. Coach also offers privates.

I've been playing tennis with Frantz since he was a coach at the Bay Club. His clinics are great and the people are nice. He divides everyone up by skill level, so there is something for everyone, no matter how you play. read more

Super clinics, fun, very well run, good ambiance. Clinics help in advancing skills and level. Have been member since start of Cal Tennis.

I've had a great experience working with Coach Frantz. I am a very beginner, beginner and started taking private lessons with him. He gives great tips, very experienced coach. I'm having a lot of fun and learning quickly. I recently started going to his group clinics too. read more

Excellent tennis clinics with lots of opportunities to play throughout the week. Good leveling of clinics too.

Franz is the best! Great instruction, plus fun drills and exercises. I highly recommend!

Frantz is a great coach for both kids and adults. Highly recommend!

Perfect for life in the city. Finding this clinic was exactly what I was looking for after struggling to find a consistent outlet for getting back into tennis. The helpful coaching and tiered skill level groups have really helped me improve my game. read more