Question: League of Denial devotes attention to the story of the football player who spent 16 years between which two teams?

Context paragraphs:
David J. Lesar: David John Lesar is an American businessman who is the Chairman of Halliburton Energy Services.  He was the CEO of Halliburton for 17 years from 2000 to 2017.  Trained as a Certified Public Accountant, Lesar spent 16 years at Arthur Andersen.  He had spent most of his career at Andersen, where he worked on their Halliburton account.  In 1995, Lesar was hired by Halliburton as a new vice president.

John Sanders (sportscaster): John Sanders is an American sports broadcaster, with over 25 years experience commentating Major League Baseball games.  He spent 16 years as a television announcer for the Cleveland Indians.  Previously, he was on both television and radio broadcasts for the Pittsburgh Pirates.  He currently broadcasts Big East football and basketball games.

Delano Rigters: Delano Lloyd Rigters (born 31 December 1956) is a former Surinamese International football player who played his entire career in Suriname, playing for Voorwaarts, MVV, Robinhood as well as for the Suriname national team.  He spent 16 years with Robinhood, finishing as the league top goal scorer four times.  He also helped his club win ten national titles, having made it to the CONCACAF Champions' Cup final on three occasions.

William A. Beardslee: William A. Beardslee (March 25, 1916 – January 25, 2001) was a professional theologian who made major contributions to the New Revised Standard Version of the Bible. As a member of the National Council of Churches, Professor Beardslee spent 16 years helping translate ancient texts to update the Bible.  The groups work resulted in the New Revised Standard Version, published in 1990, which replaced the 1952 Revised Standard edition He was professor of religion at Emory University until his retirement in 1984.  After his retirement, he spent his last 16 years as a voluntary director of the Process and Faith Program at the Claremont School of Theology.

Mike Webster: Michael Lewis Webster (March 18, 1952September 24, 2002) was an American football player who played as a center in the National Football League from 1974 to 1990 with the Pittsburgh Steelers and Kansas City Chiefs.  He is a member of the Pro Football Hall of Fame, class of 1997.  Nicknamed "Iron Mike", Webster anchored the Steelers' offensive line during much of their run of four Super Bowl victories from 1974 to 1979 and is considered by some as the best center in NFL history.

Duncan Ochieng: Duncan Aketch Ochieng (born 31 August 1978) is a Kenyan footballer who plays for Kenyan Premier League side Sofapaka as a goalkeeper.  He spent the majority of his career at Mathare United, where he spent 16 years in 4 different stints.  He also previously played for now defunct Mumias Sugar, V.League 1 side Sông Lam Nghệ An and Swedish Division 2 side IK Sleipner.  He has also made several appearances for the Kenya national team, with whom he won the 2013 CECAFA Cup on home soil.  He played the full 90 minutes in the final against Sudan, keeping a clean sheet to help his side to a 2–0 win and a 6th regional title.

Rosanne Siino: Rosanne Siino is the retired former Vice President of Communications for Netscape (Communications Corporation).  Siino is responsible for crafting the 1990s message that "the web is for everyone", as well as making the pivotal decision turn Marc Andreessen in to a "rock star," and creating the publicity strategy which landed Andreessen, barefoot, on the cover of Time Magazine.  She spent 16 years in corporate communications, 13 of which were in high-tech public relations.  Siino retired from Netscape after the 1998 acquisition by AOL and returned to graduate school.  Since retiring, she has consulted for numerous high-tech and Internet companies, such as AOL, Google, Shutterfly, Qualcomm, and PlanetOut.  Siino is also known for her philanthropy and interest in developing nations.  She currently (2009) teaches and conducts research for the Management Science and Engineering Department at Stanford University.  Her research focus is the "socio-emotional effects of digital technologies on how people work and interact."  Her past research topics specifically include work-role enactment over geographic distance, and interaction rituals on distributed management teams.

Avery Johnson: Avery DeWitt Johnson (born March 25, 1965) is an American basketball coach who is currently the head coach of the Alabama Crimson Tide men's basketball team.  Johnson spent 16 years in the National Basketball Association as a player, and subsequently served as the head coach of two NBA teams: the Dallas Mavericks and New Jersey/Brooklyn Nets.  He led the Mavericks to their first NBA Finals appearance and to three consecutive 50+ win seasons.  During his playing days, Johnson was known as the "Little General" for his small stature (by NBA standards), his leadership skills as a point guard (floor general), and his close friendship with former San Antonio Spurs teammate David Robinson - himself nicknamed "The Admiral" based on his tenure at the Naval Academy.

League of Denial: League of Denial is a 2013 book, initially broadcast as a documentary film, about traumatic brain injury in the National Football League (NFL), particularly concussions and chronic traumatic encephalopathy (CTE).  The documentary, entitled "League of Denial: The NFL's Concussion Crisis", was produced by "Frontline" and broadcast on PBS.  The book was written by ESPN reporters Mark Fainaru-Wada and Steve Fainaru.  The book and film devote significant attention to the story of Mike Webster and his football-related brain injuries, and the pathologist who examined Webster's brain, Bennet Omalu.  The film also looks closely at the efforts of researchers led by Ann McKee at Boston University's Center for the Study of Traumatic Encephalopathy, where the brains of a number of former NFL athletes have been examined.

Barry Silkman: Barry Silkman (born 29 June 1952 in Stepney, England) is a football agent and former player who played in midfield at Manchester City in 1979 and at Leyton Orient from 1981 to 1985.  He spent 16 years as a journeyman midfielder, and tried his hand at management.  In the 1990s he became an agent.

Supporting paragraphs: League of Denial Mike Webster
Answer: Pittsburgh Steelers and Kansas City Chiefs