Question: Which Canadian sports announcer started his career at 16 and now does the play-by-play on "Showtime Championship Boxing"?

Context paragraphs:
Van Miller: Van Miller (November 22, 1927 – July 17, 2015) was an American radio and television sports announcer from Dunkirk, New York, where he began his career at Dunkirk radio station WFCB calling play-by-play for high school football games.  In the 1950s, he moved to Buffalo where he became the chief play-by-play announcer for the Buffalo Bills Radio Network, the official radio broadcasting arm of the Buffalo Bills of the National Football League from the team's inception as an AFL team in 1960 to 1971, and again from 1977 to 2003.  At the time of his retirement in 2003, Miller was the longest-tenured commentator with one team (37 years) in pro football history.

Rod Smith (sportscaster): Roderick "Rod" Smith is a Canadian sports commentator.  He has been with TSN since 1987, joining as an editorial assistant for "SportsCentre" (then "SportsDesk").  He became a reporter in 1992 and has presented "SportsCentre" since 1995.  He was also a play-by-play announcer for CFL on TSN and CIS University Football.  At the Vancouver 2010 Olympic Winter Games, Smith provided the play-by-play commentary for Long Track Speed Skating.  He earned his first Gemini Award nomination in the category of Best Sports Play-by-Play Announcer later that year.  During the London 2012 Olympic Summer Games, Smith delivered play-by-play commentary from the Aquatic Centre and was honoured with the first-ever Canadian Screen Award for Best Sports Play-by-Play Announcer in 2013.  After Dave Randorf left as host of the "CFL on TSN" panel to join Rogers Media, Smith took over as host.

Showtime Championship Boxing: Showtime Championship Boxing is a television boxing program airing on Showtime.  Debuting in March 1986, it is broadcast live on the first Saturday of every month.  "Showtime Championship Boxing", which is very similar to "HBO World Championship Boxing", features Mauro Ranallo on play-by-play, Al Bernstein as the color analyst, Jimmy Lennon (Sr. and Jr.) as announcers, and Jim Gray as reporter.

Jay Larkin: Jay Larkin (October 23, 1950 – August 9, 2010) was a television boxing and entertainment executive.  During his more than twenty years with the cable network Showtime, from 1984 to 2005, Larkin created and produced such programs as "Showtime Championship Boxing" and "ShoBox" as a pay-per-view sports phenomenon, rising from publicist to senior vice president and executive producer en route to becoming one of the most powerful successful persons in the television boxing business, promoting major boxing events.  Larkin also brought MMA to television, but was less successful.

Mauro Ranallo: Mauro Domenico Ranallo (born December 21, 1969) is a Canadian sports announcer and commentator.  He is currently signed as a play-by-play announcer with MMA organization Bellator, professional wrestling promotion WWE (on their NXT brand) and also performs play-by-play duties for boxing broadcaster Showtime, most notably, the Floyd Mayweather Jr. vs. Conor McGregor bout.  He began announcing when he was 16 years old and is notable for his dramatic style, which involves heavy use of metaphor, puns, and an advanced vocabulary.  He has experience in Canadian football, ice hockey, professional wrestling, boxing, kickboxing, and mixed martial arts events.

Mark Followill: Mark Followill is an American sports announcer.  He is the primary television play-by-play voice for the Dallas Mavericks and FC Dallas.  He had previously been the radio play-by-play voice for the Mavericks on 103.3 ESPN Radio.  In 2012, he began calling FC Dallas games except when they conflicted with his responsibilities with the Mavericks.  His work with FC Dallas gained the attention of Fox Sports, who named him as one of their announcers for Copa America Centenario.  Later that summer, he was named as one of the announcers for NBC's coverage of soccer at the 2016 Summer Olympics.  He also announces play-by-play action for college football telecasts on FSN.  Earlier in his career, he was the play-by-play announcer for the SMU football team and the host of "The Ender" on KTCK The Ticket.

Pete Gross: Peter R. "Pete" Gross (December 28, 1936 - December 2, 1992) a Northwest sports announcer, was a household name in Seattle, Washington for 17 years as the "Voice of the Seahawks".  He spent most of his career as a radio play-by-play announcer with KIRO (AM).  His most memorable call line was "Touchdown Seahawks!"  Steve Raible, who served as color commentator with Pete Gross during much of his 17 years, continues to call that line as the Seahawks play-by-play announcer today.  Gross' original broadcast partners on the Seahawks radio broadcasts were Don Heinrich and Wayne Cody.

Chuck Swirsky: Chuck Swirsky (born January 30, 1954) is an American-Canadian radio sports announcer.  He is the play-by-play voice of the Chicago Bulls of the National Basketball Association (NBA).  Swirsky's association with Chicago sports started in 1979 with his WCFL AM 1000 talk show which debuted on August 27 of that year.  Outside of Chicago, Swirsky called play-by-play for both University of Michigan basketball and football and was formerly the play-by-play voice of the Toronto Raptors.

Jerry Baker (announcer): Jerry Baker is well known and recognizable as a veteran sports announcer in Indiana.  He is best known as the voice of the Indiana High School Athletic Association (IHSAA) Basketball State Championships on television having served as the anchor announcer for nearly 30 years.  He is the former voice of the Indiana Pacers and currently is a reporter for the Indy Racing League (IRL), and the Brickyard 400.  He has long held the position as the turn 1 announcer on the Indianapolis Motor Speedway Radio Network during the airing of the Indianapolis 500.  Baker, most recently, was the play-by-play announcer for HomeTown Sports and News (HTSN) on Friday nights on WRTV digital side channel 6.2 and Hometown Sports Indiana.

Jimmy Lennon Jr.: Jimmy Lennon Jr. (born August 5, 1958 in Santa Monica, California) is an American boxing ring announcer who is employed primarily by Showtime as ring announcer for its "Showtime Championship Boxing" events.  Lennon was also employed by Fox Sports when the Fox network had rights to professional boxing and was the ring announcer for Don King Promotions' fights that aired on various networks (including HBO, although King has largely promoted fights for Showtime since 1991).  He is best known for his catchphrase, "It's show time!"

Supporting paragraphs: Showtime Championship Boxing Mauro Ranallo
Answer: Mauro Ranallo