Neff and the Red Men captured the CCIW Men's Lacrosse Regular Season Championship from 2015-17, which led to three-consecutive appearances in the NCAA Division III Men's Lacrosse Tournament. He guided Carthage to the 2016 CCIW Tournament Championship with a 13-8 victory over Illinois Wesleyan. Neff's efforts landed him 2015 and 2017 CCIW Coach of the Year.

Neff has guided Carthage to several statistical team top-10 finishes. The Red Men led NCAA Division III in extra man opportunities (2011, .541) and ranked second in scoring defense (2014, 5.86), total assists (2013, 201) and assists per game (2013, 10.74). The 2013 Red Men finished third nationally in caused turnovers (313) before the 2017 squad's 6.53 scoring defense ranked fifth in the country.

Neff arrived to Carthage following a two-year stint as the St. Charles North (IL.) High School head boy's lacrosse coach (2005-2006), where his team won the 2006 DuPage Conference Championship. Prior to that, Neff coached at Neuqua Valley High School in Naperville, Ill. from 2002 to 2004. The inaugural 2002 Neuqua Valley team registered a 14-6 overall record, which helped Neff land IHSLA Coach of the Year. He followed that with the school's first-ever DuPage Conference Championship in 2003. Neff owns a 56-25 overall record as an IHSLA head coach. In addition, Neff was the head coach of Team Illinois from 2006-2007.

Neff, a native of Waukegan, Ill., received a bachelor’s in finance from the University of Illinois in 1995 and a master’s in business administration, also from Illinois in 1998. Neff was a member of the Illini club lacrosse team and a 1997 United States Intercollegiate Lacrosse Association All-Star. He has been active in several Chicago-area summer camps, including Lacrosse America youth clinics.

His father, John Neff, graduated from Carthage in 1963 and was a 1997 inductee into the Illinois High School Football Coaches Hall of Fame. Neff, who also serves as an adjunct professor in Carthage’s business administration program, resides in Kenosha with his wife, Erin, their daughter, Pippa, and twins Gavin and Georgiana.