A Closer Look at the Relative Age Effect in the National Hockey League

• Activity Number: 195
• Type: Contributed
• Date/Time: Monday, August 2, 2010 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics in Sports
• Author(s): Vittorio Addona*+ and Philip Yates
• Companies: Macalester College and California State Polytechnic University, Pomona
• Keywords: relative age effect ; NHL ; change point

Abstract

At young ages, a few extra months of development makes a big difference in athletic ability. A boy who turns 5 years old in January will be 20% older than a boy born in December. In many sports, including hockey, boys born early in the calendar year get noticed because of their age aided superiority. As a result, these boys are more likely to reach the NHL. This phenomenon is labeled the relative age effect (RAE). Previous work focused on individual NHL seasons, encompassing the same players across multiple years. We investigate the RAE using data on every player who ever played in the NHL through the 2008-09 season. A change point analysis provides, for the first time, an estimate of when the RAE began: births since 1951 (95% CI [1949,1956]). We also make a case for what initiated this change in the way players develop, particularly in Canada, which has produced the most NHLers by far.