Question: Thursday Night Baseball includes a play-by-play announcer who has been on NBC Sports since what time period?

Context paragraphs:
Bob Costas: Robert Quinlan Costas (born March 22, 1952) is an American sportscaster, on the air for NBC Sports television since the early 1980s.  He was the prime-time host of 12 Olympic Games, from 1992 until 2016.  Costas currently does play-by-play for MLB Network and hosts an interview show called "Studio 42 with Bob Costas".

Ari Wolfe: Ari Wolfe (born 1971) is a play-by-play announcer, reporter and anchor.  He currently calls games for CBS Sports Network, ESPN, Root Sports and NBC Sports.  Additionally, he serves as an anchor and reporter for the NFL Network.  He is a two-time Emmy award winner.  He won his first Emmy for his work calling Louisville Football and Basketball in 2005, he earned his 2nd Emmy award in 2014 for his work as a play-by-play announcer on Mountain West College Football games on Root Sports.

Rick Allen (sportscaster): Rick Allen Schwieger, known professionally as Rick Allen (born June 17, 1969), is a television personality, play-by-play announcer, and voice-over artist.  He currently works for NBC Sports as the play-by-play commentator for NASCAR's Monster Energy Cup Series and Xfinity Series, on an interim basis for the Verzion IndyCar Series, and for NBC Sports coverage of track & field.  He previously had done play-by-play broadcasting for Fox Sports's coverage of NASCAR's Camping World Truck Series and voice-over work for Goodyear, Sears, Alltel, and Toyota among many others.

Dave Strader: Dave Strader (February 24, 1955 – October 1, 2017) was an American sportscaster.  He was the TV (and radio simulcast) play-by-play announcer for the Dallas Stars of the National Hockey League (NHL).  He replaced Ralph Strangis beginning with the 2015-16 season.  Until the 2015 Stanley Cup playoffs, he was the No. 2 play-by-play announcer (behind Mike Emrick) for the "NHL on NBC" and "NHL on NBC Sports Network."  Strader also called games for the "NHL on Versus" before Versus changed names to NBC Sports Network (NBCSN).  Also, from 1997-2004 and, after a lockout cancelled the 2005 Finals, again from 2006-2015 he broadcast the Stanley Cup Finals in English on the NHL's international feed.  On April 17, 2017 the Hockey Hall of Fame announced that Strader was the 2017 recipient of the Foster Hewitt Memorial Award for his outstanding contributions to play-by-play broadcasting of the game of ice hockey during his professional career, which began in 1979 with the AHL Adirondack Red Wings.

Matt Vasgersian: Matthew Edward "Matt" Vasgersian (born September 28, 1967) is an American sportscaster and television host.  Vasgersian is currently a play-by-play announcer for Fox Sports' coverage of Major League Baseball, as well as a studio host for the MLB Network.  In the past he has served as an announcer for Fox Sports' National Football League coverage, NBC Sports' coverage of the Olympic Games, and NBC Sports' coverage of the short lived XFL.  He formerly called play-by-play for the Milwaukee Brewers and the San Diego Padres.

Tom Hammond: Tom Hammond (born May 10, 1944) is an American sportscaster for NBC Sports television.  Hammond is one of the network's staple on-air presenters, along with Bob Costas and Dan Hicks.  Hammond was the lead play-by-play commentator for Southeastern Conference men's basketball broadcasts by TVS (1980-1983), SPI/Lorimar (1984-1986) and Raycom Sports (formerly Lincoln Financial Sports and Jefferson Pilot Sports) from 1987 until 2009.  In 2013, he was replaced by Dan Hicks as play-by-play announcer for Notre Dame football on NBC.  He has known his color commentator on the Lincoln Financial broadcasts, Larry Conley, since junior high school.  Hammond also served as the play-by-play announcer for NBC's coverage of track and field at each Summer Olympics from 1992 to 2016.

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.

Bill Seward: Bill Seward is an American sportscaster, actor and former coach.  Seward is a play-by-play announcer for NBC Sports.  In addition to calling various professional and college sports in America, Seward has been “on the mic” for NBC’s Olympic rugby coverage, "Rugby World Cup" on NBC, "Rugby World Cup Sevens" on NBC Sports Network, Varsity Cup, Red Bull Cliff Diving World Series, FIS Alpine Skiing World Cup, FIS Nordic Skiing World Cup, European Figure Skating Championships, FINA Synchronized Swimming World Cup, Vuelta a Espana, Eneco Cycling Tour, Tour of Belgium, Tour of Norway, 4 Days of Dunkirk, Paris Marathon, IBU Biathlon World Championships, Tour de Ski and the Four Hills World Cup ski jumping event.  Seward also has appeared on NBC’s "Early Today" along with programs on MSNBC, CNBC, USA Network, Universal Sports and the horse racing networks HRTV and TVG.

Thursday Night Baseball: Thursday Night Baseball (formally known as MLB Network Showcase) is the title of a presentation of Major League Baseball on cable and satellite channel MLB Network (self-produced by MLB Network), that premiered on April 9, 2009.  Longtime NBC Sports broadcaster Bob Costas is one of the play-by-play voices of the broadcasts.  Matt Vasgersian also does play-by-play on some games.  Jim Kaat, John Smoltz, and Tom Verducci provide color commentary.  The network produces 26 non-exclusive live games a year during baseball season.  Since one or both teams' local TV rights holders also carry the games, the MLB Network feed is subject to local blackouts.  In that event, the cities in the blacked-out markets will instead see a simulcast of another scheduled game via one team's local TV rights holder.

Ryan Burr: Ryan Burr (born March 17, 1972, Pittsburgh, Pennsylvania) is a sports television journalist.  Burr has worked for the NBC Sports Group since 2012, with his duties mainly consisting of golf and college basketball coverage.  For golf, he is the main studio host on NBC's Golf Channel, as well as an occasional play-by-play voice.  For college basketball, he mainly works as a play-by-play announcer on East Coast telecasts airing on the NBC Sports Network.  Before joining the NBC Sports Group, Burr was previously a studio host for ESPN.  In his spare time, he enjoys being the worst commissioner in ESPN fantasy football history.

Supporting paragraphs: Thursday Night Baseball Bob Costas
Answer: early 1980s