Slammers Coaches and Instructors

Our team of professional Coaches and instructors take pride in helping players of all ages and skill levels enhance their playing experience. Our goal is to provide every player a solid foundation to work from, as well as an understanding of the mechanics involved at each position. In addition, we want every player to have the opportunity to reach their maximum potential.

Mark Holzemer

Mark is a proud Littleton native and President of Slammers Baseball & Softball. Mark is former Major League left-handed pitcher who was drafted in the 4th round of the 1987 draft after graduating from Mullen High School. Mark played at Seminole Junior College in 1988 where he pitched in the Junior College World Series and earned 1st team All-American honors. Mark began his 15 year professional career with the California Angels in 1988 where he was both a starter and relief pitcher.

In addition to the Angels he pitched in the major leagues for the Seattle Mariners, Oakland Athletics and Philadelphia Phillies as well as playing for the Yokahama Baystars in the Japanese Major Leagues in 2001. Mark played three seasons of winter ball in Venezuela and one season in Mexico. Upon retiring in 2002 Mark became co-owner of Slammers baseball & Softball.

Mark’s passion is working with players of all ages to teach them the great game of baseball. Since joining the Slammers organization Mark has given more than 7000 private lessons and multiple camps and clinics. Mark has coached 6 year old teams through High School select teams. Marks teams have won the 9,12,13 and 14 USSSA Majors State Championships and he finished 5th in Cooperstown. He has competed with the Slammers teams in National tournaments across the country. Mark is currently an associate Scout for the Kansas City Royals.

Clint Zavaras


Clint Zavaras is a Colorado native who pitched at Mullen High School. His accolades coming out of high school include Dr. Pepper Player of the year and Colorado high school player of the year. He was acquired in the 3rd round by the Seattle Mariners of the 1985 draft. Clint made his major league debut against the Texas Rangers and Nolan Ryan in 1989. He signed with the Colorado Rockies in 1993.

Clint finished career with the Seattle Mariners in 1995. Clint was honored by being the opening day starting for the Greek National Team in the 2004 Olympics. Clint has spent the last 15 years giving private instruction to the areas top high school, college, and professional players and has done well over 20,000 private lessons. Clint is a pioneer in the bio-mechanics of pitching; developing one of the nations top Arm Velocity Programs. Clint is an owner of Slammers and a Associate Scout for the Kansas City Royals.


Billy Martin


Billy Martin played 4 years at the University of Texas at Arlington. He was drafted in the 34th round by the New York Mets. Taken in the rule 5 draft by the Arizona Diamondbacks in 1999 and then sold to the Yakult Swallows of the Japanese Central league in 2003. He was later signed by the Washington Nationals for the 2005 season.

Billy was a 3 time minor league all-star with a career .285 avg. and 94 home runs. Billy played 8 years professionally at 4 positions(1b,3b,lf,rf). Billy is now a owner, COO, and full time instructor/coach at Slammers. He specializes in hitting and fielding at all levels and works with youth pitchers as well. Billy has a bachelors degree in kinesiology from the University of Texas at Arlington and a MBA from CU Denver. Billy is also a certified National Strength and Conditioning(NSCA)personal trainer.

Billy is currently an Associate Scout for the Kansas City Royals.


Garrett Duman

Garrett was hired full time at Slammers in April 2019 after a long high school coaching career. He was most recently the Head Baseball Coach at Rock Canyon High School after spending 12 years on staff at Cherry Creek under legendary coach Marc Johnson. Duman also graduated from Cherry Creek where he was a catcher for the Bruins. After high school he played collegiately at Nebraska Wesleyan University where he earned the Pflieger-Olson Scholar Athlete Award for excellence in both Academics and Athletics. In addition to coaching at Cherry Creek, he spent two years as the JV coach at Boulder High School under Coach Steve Disbrow. During his tenure at Creek, the Bruins saw unparalleled success including a 5A state title, 86 collegiate signees, 8 league titles and 11 consecutive state tournament appearances. That streak was snapped in 2018 when Coach G’s Rock Canyon Jags upset Cherry Creek in the Regional Championship. Coached Cherry Creek 17’s to the 2012 AAABC Don Mattingly National Championship in Port St. Lucie,  Florida in the summer of 2012.

Scott Bauer

Coach Bauer played at Highlands Ranch High School 1993-1997 where he was a catcher.  He later went on to play college baseball at Hastings College from 1997-2001 (Catcher, DH).

 He started coaching the Summer of 1997 right after high school at Highlands Ranch High School as the Head JV coach.  He coached over 10 summers and 4 springs at HRHS (JV and Varsity levels).  He later began coaching with John Cronican in 2003 for the Rocky Mountain Steel and eventually 5280 Baseball Club Teams.  Additionally, he spent one year as Assistant Varsity Coach at Arvada High School, two years as assistant Varsity Coach at Palmer Ridge High School, an then spent one season as a Pitching Coach at Mountain Vista High School.

 Coach Bauer started coaching at Slammers in the Summer of 2015 coaching the Graduated Seniors and continuing with Seniors during the fall.  He is currently a 17U Slammers Summer/Fall High School Select coach. He has over 20 years of coaching experience. Coach Bauer also is our catching and defensive coordinator at Slammers.

Connor Bitzer


Coach Bitzer was born and raised in the beach cities of Orange County, CA where he attended Fountain Valley High School from 2008-2012. Prepping early on as a two-way player [CF & LHP], he later shifted his focus solely to the outfield, continuing his career at the NCAA D1 level as a position player. He attended the University of The Pacific from 2012-2016 where he competed in the Big West & West Coast Conferences as well as played alongside fellow Slammers Coach/Instructor, Jake Jenkins. Connor enjoyed early success with the Tigers, earning time as a true freshman and looked to be a mainstay in the lineup in the years to come. He played for the East Texas Pump Jacks in the 2013 Texas Collegiate League, however, a freak back injury sidelined him for much of next year, and ultimately cut his career short altogether. 

Following his departure from a playing career, Coach Bitzer stepped into his first role as a coach, helping coordinate and implement the birth of the Venture Academy [Stockton, CA] baseball program. From 2014-2016, he assisted the team in growing from a first-year program, to back-to-back appearances in the CIF Sac-Joaquin Section Semi-Finals. Notably, in the following year, VA again returned to the section tournament and advanced to the championship game with the underclassmen whom Coach Bitzer previously mentored.Connor joined the Slammers staff in the Fall of 2017. A hitting director within the spring youth program, Coach Bitzer is also a head coach for our HS Summer Select and Fall Select Programs. During his first summer at the helm of a roster, his 2022-Grad team finished with a PerfectGame Top-10 ranking in the Mountain-West Region, as well as a national honorable mention. Specializing in hitting mechanics & defensive work, Connor is available as a hitting & fielding instructor.


Mike Fiscus

Mike Fiscus is a Colorado native that has been coaching and instructing baseball in Colorado for over 25 years. He has coached at various levels from 10 yr old competitive through graduated senior/college prep levels. He got his start on the High School side in the late ‘90’s at Fairview HS in Boulder, CO., coaching the Freshman and Sophomore teams and assisting with the JV and Varsity. During the summer, he coached the Legion C and Legion B levels, assisting in a Legion B state championship during that time. In 2000, he moved to Parker and though not actively working in baseball with a school or program, he continued giving private instruction while fostering ambitions to someday get back to his passions of coaching. Beginning in 2009, he began to actively pursue being involved in the game, eventually gaining a position at Rock Canyon HS as a “C” team Head Coach. From there he was a Varsity Assistant at Heritage HS, which then led to a Varsity Assistant position at Chaparral HS in 2014, where he currently remains. During the Summer and Fall months, he coaches for Slammers Baseball at the 16u-18u levels and gives private instruction for all ages, year round. He currently lives in Parker with his very understanding and lovely wife Amy, and his two daughters Paige and Rachel.

Brian Givens

Jake Jenkins

Jake Jenkins played for Slammers for 4 years and at Legend High School where he was All-State pitcher. He earned a scholarship to play D1 baseball at the University of Pacific in the WCC Conference.

Jake was a four-year starting pitcher for the UoP Tigers earning All 1st Team Conference and runner-up pitcher of the year as a sophomore. His junior and senior years Jake was All Conference Honorable Mention.

Jake Played summer collegiate baseball for Watertown Rams in the PG League, Mankato Moondogs in the Northwoods league, and the Brewster White Caps in the Cape Cod League.

Jake is a pitching, hitting, and fielding instructor and a coach for our Slammers High School Summer Select Program and High School Fall Select teams. Jake was previously the varsity pitching coach for Chaparral High School. He will be the head coach this summer for a Slammers Summer High School Summer Select 2020 grad team.

Max Kuhns

Max Kuhns was drafted by the New York Mets in the 21st round of the 2016 MLB Draft and pitched professionally in the organization from 2016-2019. While with the Mets, Max was a 2017 South Atlantic League All-Star while posting a 2.10 ERA during the season and also earned the 2017 May Pitcher of the Month for the organization. Max had a career 3.56 ERA and a 10.5 strikeouts per 9 innings. Before the Mets, Max played collegiately at Santa Clara University. During his first two seasons at Santa Clara, he was the only player on the roster to serve as both a position player and a pitcher. In his junior season, Max converted into a pitcher only and set the single season save record of 14, while posting a 2.21 ERA. In high school, Max was a two-time All-Colorado/All-State Pitcher/3B, three-time first team All Continental League, Continental League MVP, and two-time captain for Chaparral High School.

Max’s coaching career started in 2014 while playing at Santa Clara. He joined the Slammers coaching staff in 2017, his second off-season with the New York Mets, where he was the pitching coach on a Slammers 2019-Grad team. From that team, 17 players went on to collegiate baseball programs including 8 to Division 1 programs. In 2019, Max was the pitching coach on Scott Bauer’s Slammers 2021-Grad team, and he will be continuing with that team going into the summer of 2020.

Tyler Dunsmoor
Bob Smith

“Baseball Bob” is a Colorado Native, and has been Slammers coach & instructor for 18 years. Current Yankees Associate Scout for the last 8 years, after previously scouting for the Braves & Indians. Bob has been involved in the youth program for over a decade and specializes in hitting & fielding. Currently helps the Cherry Creek High School program during their indoor winter training as he has done for the last 10 years. Both sons, Cameron & Alec are Slammers alum and attended University of New Mexico & Oral Roberts. He loves to help youth players get better at the game both mentally & physically with a huge passion for the game and the preparation for the next level. Bob currently works as a loan officer with the Bank of England– reach out if you need some extra fundraising ideas.

Jonathan Hayden
Evan Kenebrew



Seth Barnes

Jesse Bristow

Jake Hand

Jake Hand is a Highlands Ranch, Colorado native. Played baseball and football at ThunderRidge High School from 2009-2013. Played D1 baseball at Southern Illinois University as a catcher and outfielder from 2013-2017. Graduated with a degree in exercise science and has been a certified strength and conditioning coach for over 2 years. 

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Kyle Schmidt

Kyle Schmidt

Originally from Smithville, TX, Kyle has had a passion for catching his entire life. After High School, Kyle attended the University of Richmond and became a starter for the Spider Baseball Team. Following his 2019 season, Kyle was drafted in the 33rd Round of the 1st Year Player Draft by the Minnesota Twins. Kyle finished up the 2022 season with the Wichita Wind Surge (Class AA). Kyle brings his professional mindset to catching instruction where he encourages modern catching techniques that are used at the highest levels – one-knee setups and high-level receptions are his specialties. That said, Kyle strives to build foundational catchers who are proficient in all aspects of the position. With an understanding of the mechanics of the catching position, players will become familiar with and improve their mobility, receiving, throwing, blocking, setup, and mentality.

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Kajeon Johnson
Jake Eisller
Eric Moberly
Matt Givin
Chris Givin
Bo Weiss
Tyler Smith
Ron Quintana
Tyler Hurley
Brian King
Christian Meyers
Brett Grammerstorf
Nino Giarratano

Recruiting Coordinator Nino GiarratanoCoach Giarratano’s vast experience and success as a Division 1 coach recruiting and developing players make him the perfect fit to assist families in navigating the recruiting process.

Coach Giarratano coached at the Division 1 level for 26 seasons. He was the Head Coach at the University of San Francisco from 1999-2022 where he was a three-time West Coast Conference Coach of the Year. Before coming to USF, he was an assistant coach at Arizona State University from 1997-1998, serving as the hitting instructor, offensive coordinator and third base coach. Prior to coaching at the Division 1 level, Giarratano was the Head Coach at Trinidad State Junior College from 1989-1994 and named Collegiate Baseball’s National Junior College Coach of the Year three times. Between Trinidad State and ASU, he spent two seasons from 1995-1996 at Yavapai College where he sent 25 players to the professional ranks.