Jeff grew up in Brooklyn and discovered horseracing while still in high school. After attending John Jay College , he took a job as a mutual clerk for NYRA in 1979. Jeff moved onto the backstretch in 1980 working as assistant to Elliot Burch and Gasper Moschera.

He received his trainer's license in 1986, and started training at a small public stable in New Jersey 's Monmouth Park and The Meadowlands. He then moved on to training at Aqueduct and was a top-10 trainer for three years running – from 1991 to 1993. In 1996, he took a break from training to become a jockey agent, representing Eddie Maple. Jeff returned to training in 1998, and today uses his extensive Thoroughbred knowledge and experience as Karakorum 's primary trainer.