Question: Under what head coach did the Baltimore-based franchise make it to the playoffs 23 years after their last appearance as the Baltimore Colts?

Context paragraphs:
2015 Buffalo Bills season: The 2015 Buffalo Bills season was the franchise’s 56th overall season as a football team, 46th in the National Football League, third under leadership of general manager Doug Whaley and first under new head coach Rex Ryan, who signed a five-year, $27.5 million contract on January 12, 2015 after having previously spent the past six seasons coaching the division-rival New York Jets, leading them to two straight AFC Championship games in 2009 and 2010, becoming the franchise’s 18th head coach and the fifth in the past seven years in the process.  Ryan replaced Doug Marrone, who opted out of his contract on December 31, 2014 to take advantage of a contract loophole, fearing the Pegulas were going to fire him, hence the reason the Bills entered the 2015 season looking for a new head coach.  Despite the bold prediction made by Ryan at his introductory press conference, where he stated, “I’m not going to let our fans down.  I am not going to do that.  I know it’s been 15 years since the Bills made the playoffs.  Well, get ready, man, we’re going.  We are going,” the Bills were unable to make the playoffs in their first season with Ryan as head coach, finishing with a record of 8-8 (the team’s first since 2002), making it the 16th straight season without a playoff appearance, which became the longest active in major professional sports after Major League Baseball’s Toronto Blue Jays broke their 22-year playoff drought on September 25, 2015.  It was also the first full season under the ownership of Terry and Kim Pegula (whom also own the Buffalo Sabres), having purchased the Bills partway through 2014 after the death of longtime owner Ralph Wilson in March at the age of 95.  The Bills began their season with an open competition for the starting quarterback position after Kyle Orton, the starter for most of the 2014 campaign, retired during the offseason, so the team acquired free agent Tyrod Taylor, a former backup quarterback of the Baltimore Ravens, who won the competition over incumbent second-string quarterback EJ Manuel and trade acquisition Matt Cassel, the latter of whom the team later traded along with a seventh-round pick in 2017 to the Dallas Cowboys, in exchange for a fifth-round draft pick in 2017.

Don Shula: Donald Francis Shula (born January 4, 1930) is a former professional American football coach and player best known as the head coach of the Miami Dolphins, the team he led to two Super Bowl victories, and to the only perfect season in the history of the National Football League (NFL).  He was previously the head coach of the Baltimore Colts, with whom he won the 1968 NFL Championship.  Shula was drafted out of John Carroll University in the 1951 NFL Draft, and he played professionally as a defensive back for the Cleveland Browns, Baltimore Colts, and Washington Redskins.

Baltimore's Marching Ravens: Baltimore's Marching Ravens are the official marching band of the Baltimore Ravens American football team.  They were founded as the Baltimore Colts' Marching Band on September 7, 1947 and have continuously operated ever since, supporting three separate football franchises.  The band first supported the original Baltimore Colts from 1947 to 1950, but continued to operate even after the franchise disbanded in 1950.  After a new Baltimore Colts franchise was installed in 1953, the band became associated with the newly founded team.  The band endured a second relocation when the Colts moved to Indianapolis in the middle of the night in 1984, leaving Baltimore without a team for eleven years.  The band became attached to a third franchise when the Cleveland Browns relocated to Baltimore in 1996 and became the Ravens.  They are one of two official marching bands in the NFL, the other being the Washington Redskins Marching Band.

History of the Baltimore Colts: The professional American football franchise currently known as the Indianapolis Colts was originally based in Baltimore, Maryland, from 1953 to 1984.  This article chronicles the franchise's history during its time as the Baltimore Colts.  Named in honor of Baltimore's history of horse breeding and racing (including the Preakness Stakes, one of the events in the U.S. Triple Crown championship series) at Pimlico Race Course, this was the second incarnation of the "Baltimore Colts" after the first one played from 1947 to 1950 in the old All America Football Conference for three years and moved to the National Football League (NFL) with a few other AAFC teams after the 1949 merger, but playing only one season.  The 1953-83 Baltimore Colts team played its home games at Memorial Stadium on 33rd Street during its entire tenure in Baltimore before the franchise relocated to Indianapolis, Indiana, in March 1984.

Baltimore Colts relocation to Indianapolis: The Baltimore Colts relocation to Indianapolis was a successful effort by the then-owner of the Baltimore Colts (Robert Irsay) to move the American football team from Baltimore, Maryland to Indianapolis, Indiana.  The team began play as the Indianapolis Colts for the 1984 National Football League (NFL) season.  The Colts' move was completely unannounced and occurred in the early hours of March 29, 1984, after years of lobbying for a new stadium to replace the inadequate Memorial Stadium.  The franchise's move continues to embitter many Baltimore natives decades afterward, and would have a lasting impact on the NFL, including another controversial relocation twelve years later that resulted in Baltimore receiving its current NFL team, the Ravens.

List of Indianapolis Colts head coaches: The Indianapolis Colts are a professional American football team based in Indianapolis, Indiana.  They are a member of the South Division of the American Football Conference (AFC) in the National Football League (NFL).  In 1953, a Baltimore-based group led by Carroll Rosenbloom won the rights to a new Baltimore franchise.  Rosenbloom was granted an NFL team, and was awarded the holdings of the defunct Dallas Texans organization.  The team was known as the Baltimore Colts for 31 seasons before moving to Indianapolis in March 1984.

1977 Baltimore Colts season: The 1977 Baltimore Colts season was the 25th season for the team in the National Football League (NFL).  The Colts finished the NFL's 1977 season with a record of 10 wins and 4 losses, and tied for first in the AFC East division with the Miami Dolphins.  However, the Colts finished ahead of Miami based on better conference record (9–3 to Dolphins' 8–4).  This season would mark the final season in which the Colts would make the playoffs as a Baltimore-based franchise (the Colts next appearance in the playoffs came 10 years later in 1987, by which time the team moved to Indianapolis).  Baltimore would not have a team in the playoffs again until the Baltimore Ravens advanced to Super Bowl XXXV, just over 23 years later.

1973 Detroit Lions season: The 1973 Detroit Lions season was their 44th in the league.  Don McCafferty, who served as an assistant under Don Shula during Shula's stint as head coach of the Baltimore Colts, and whom as head coach himself coached the Colts to a Super Bowl V victory over the Dallas Cowboys, would replace Joe Schmidt as head coach.  However, the team would still fail to improve on their previous season's output of 8–5–1, finishing a mediocre 6–7–1.  The team missed the playoffs for the third straight season.

2000 Baltimore Ravens season: The Baltimore Ravens season was the franchise's 5th season in the National Football League (NFL) and the second under head coach Brian Billick.

List of Indianapolis Colts seasons: The Indianapolis Colts, formerly the Baltimore Colts, are an American football team playing in the National Football League (NFL).  This list documents the season-by-season records of the Colts franchise from to present, including postseason records and league awards for individual players or head coaches.  In 1953, a Baltimore-based group led by Carroll Rosenbloom gained the rights to a new Baltimore franchise.  Rosenbloom was granted an NFL team, and was awarded the holdings of the defunct Dallas Texans organization.  The new team was named the Colts after the previous team that folded after the 1950 NFL season.  After 31 seasons in Baltimore, Colts owner Robert Irsay moved the team to Indianapolis, Indiana.

Supporting paragraphs: 1977 Baltimore Colts season 2000 Baltimore Ravens season
Answer: Brian Billick