Question: The head coach of the Washington State Cougars football team helped popularize what offensive scheme?

Context paragraphs:
1958 Washington State Cougars football team: The 1958 Washington State Cougars football team was an American football team that represented Washington State University in the Pacific Coast Conference (PCC) during the 1958 college football season.  In their third season under head coach Jim Sutherland, the Cougars compiled a 7–3 record and outscored their opponents by a combined total of 199 to 117.

1919 Washington State Cougars football team: The 1919 Washington State Cougars football team was an American football team that represented Washington State College during the 1919 college football season.  Head coach Gus Welch led the team to a 2–2 mark in the PCC and 5–2 overall.  This year marked the team's adoption of the "Cougars" nickname.

Air raid offense: In American football the air raid offense refers to an offensive scheme popularized by such coaches as Mike Leach, Hal Mumme, Sonny Dykes, and Tony Franklin during their tenures at Valdosta State, Kentucky, Oklahoma, Texas Tech, Louisiana Tech, and Washington State.

1947 Washington State Cougars football team: The 1947 Washington State Cougars football team was an American football team that represented Washington State College in the Pacific Coast Conference (PCC) during the 1947 college football season.  Phil Sarboe, in his third of five seasons as head coach at Washington State, led the team to a 2–5 mark in the PCC and 3–7 overall.

Mike Leach (American football coach): Michael Charles Leach (born March 9, 1961) is an American college football coach.  He is the head coach of the Washington State Cougars football team.  Previously, he was head coach of the Texas Tech Red Raiders football team, leading the Red Raiders to winning seasons in every year of his tenure.

1994 Washington State Cougars football team: The 1994 Washington State Cougars football team was an American football team that represented Washington State University in the Pacific-10 Conference (Pac-10) during the 1994 NCAA Division I-A football season.  In their sixth season under head coach Mike Price, the Cougars compiled a 8–4 record (5–3 against Pac-10 opponents), finished in fourth place in the Pac-10, and outscored their opponents by a combined total of 192 to 136.

1988 Washington State Cougars football team: The 1988 Washington State Cougars football team was an American football team that represented Washington State University in the Pacific-10 Conference (Pac-10) during the 1988 NCAA Division I-A football season.  In their second season under head coach Dennis Erickson, the Cougars compiled a 9–3 record (5–3 against Pac-10 opponents), finished in a tie for third place in the Pac-10, and outscored their opponents by a combined total of 415 to 303.  On October 29, Washington State beat No. 1 UCLA at the Rose Bowl, their first and only win ever over a No. 1 ranked team.

1978 Washington State Cougars football team: The 1978 Washington State Cougars football team was an American football team that represented Washington State University in the Pacific-10 Conference (Pac-10) during the 1978 NCAA Division I-A football season.  In their first and only season under head coach Jim Walden, the Cougars compiled a 4–6–1 record (2–6 against Pac-10 opponents), finished in last place in the Pac-10, and were outscored by their opponents by a combined total of 296 to 276.

1920 Washington State Cougars football team: The 1920 Washington State Cougars football team was an American football team that represented Washington State College during the 1920 college football season.  Head coach Gus Welch led the team to a 1–1 mark in the PCC and 5–1 overall.  This year marked the team's adoption of the "Cougars" nickname.

1997 Washington State Cougars football team: The 1997 Washington State Cougars football team was an American football team that represented Washington State University in the Pacific-10 Conference (Pac-10) during the 1997 NCAA Division I-A football season.  In their ninth season under head coach Mike Price, the Cougars compiled a 10–2 record (7–1 against Pac-10 opponents), won the Pac-10 championship, lost to Michigan in the 1998 Rose Bowl, and outscored their opponents by a combined total of 483 to 296.  The Cougars and played their home games at Martin Stadium in Pullman, Washington.

Supporting paragraphs: Air raid offense Mike Leach (American football coach)
Answer: air raid offense