When Bill Walsh was promoted to the front office in 1989, longtime defensive coordinator George Seifert was chosen to fill his head coaching role.
Twenty-seven years later, the San Francisco 49ers this week hired former Cleveland Browns defensive coordinator Jim O'Neil to the same position.
Here is the complete timeline for how the 49ers over the years transitioned from Seifert all the way to O'Neil.
DC: Bill McPherson
Rank in points: 3rd, 2nd, 4th, 3rd, 16th
Rank in yards: 4th, 3rd, 6th, 15th, 15th
DC: Ray Rhodes
Rank in points: 6th
Rank in yards: 8th
DC: Pete Carroll
Rank in points: 2nd, 4th
Rank in yards: 1st, 7th
DC: John Marshall
Mike Holmgren, Mike Shanahan, Jeff Fisher, Pete Carroll and others all once graced the San Francisco sideline.
Rank in points:** 3rd, 13th
Rank in yards: 1st, 23rd
DC: Jim Mora
Rank in points: 30th, 28th, 9th, 18th, 21st
Rank in yards: 28th, 29th, 13th, 14th, 13th
DC: Willy Robinson
Rank in points: 32nd
Rank in yards: 24th
DC: Bill Davis
Rank in points: 30th, 32nd
Rank in yards: 32nd, 26th
DC: Greg Manusky
Rank in points:** 20th, 23rd, 4th, 16th
Rank in yards: 25th, 13th, 15th, 13th
DC: Vic Fangio
Rank in points: 2nd, 2nd, 3rd, 10th
Rank in yards: 4th, 3rd, 5th, 5th
DC: Eric Mangini
Rank in points: 18th
Rank in yards: 29th
DC: Jim O'Neil
Rank in points: TBD
Rank in yards: TBD
Stats from Pro-Football-Reference.com. Additional research provided by former 49ers.com digital editor Andrew Pentis.