As one of the rare athletes in high school who excels at football, basketball, and baseball. John was very highly touted his junior and senior years. In 1982, his football accomplishments brought John the distinction of being named the USA Today Football Player of the Year. In 1983, his basketball instincts resulted in All-State basketball honors while being the key member on the Menlo School State Basketball Championship Team. Also in 1983, John showed he was gifted enough baseball player to be drafted straight out of high school by the San Francisco Giants.

Upon graduation from Menlo High School, John chose to attend Stanford University on a football scholarship. From 1983 to 1987, he excelled both academically and athletically. In addition to pursuing a Bachelor of Arts degree in economics, John was a three-year letterman as point guard on the basketball team and an academic All-American candidate as a quarterback on the football team. A four-year starter at quarterback, John was team captain during the 1986 season when the Cardinals were ranked 16th nationally and appeared in the Gator Bowl. Continuing Stanford's rich quarterback tradition, John left Stanford the second all-time career passing yardage leader, behind perennial All-Pro John Elway. John set records that include most completions (271) in a single season, most attempts (405) in a single season, and most completions (40) in a single game. John was inducted into the Stanford University Sports Hall of Fame in 2008.

After an impressive career at Stanford, John was drafted by the San Francisco 49ers in 1987. With the Niners, John was a member of the two-time NFC Western Division Champions and Super Bowl XXIII Champions team. After three years as a backup for future Hall-of-Famer Joe Montana and All-Pro Steve Young, John was forced to retire from professional football in 1989 due to complications from shoulder surgery. In 1991, John's home county recognized his past accomplishments and welcomed him to its family of successful business people when he was elected to the San Mateo County Hall of Fame.

Through John’s work with First Down Promotions, he remains active in athletics, albeit in more instructive capacity. Divisions of First Down Promotions provide youth sports instruction in both basketball and volleyball. John organizes and coordinates in excess of 20 AAU youth basketball teams each year. His sports facility provides year round basketball activities with camps, clinics, tournaments. John oversees the activities and coaches multiple teams throughout the years. Since 1987, John has coached girl's basketball team at Menlo School in Atherton, CA and has taken them on a most impressive run. Under John's tutelage, the girls won an unprecedented three straight California Division V State Championships (1989-1991). John also serves on the board of directors for the Redwood Chapter of the National Junior Basketball program, NJB. Through his various athletic programs and by example John continues to impart his ideas on teamwork and success to young athletes in the Bay Area.