With Kirby Smart taking over the Georgia Bulldogs and Will Muschamp getting the South Carolina gig, two more former Nick Saban assistants are ascending (or re-ascending) to head coaching jobs. With that in mind, it's worth looking at how the all of the branches of the Saban coaching tree have panned out as head coaches.
Here is my ranking of the major past Saban assistants who have gone on to be head coaches.
1A. Jimbo Fisher
The only past Saban assistant to win a national title, Fisher deserves a spot at the top of the list. He wasn't a direct hire from a Saban staff, having stayed on at LSU for a couple of years with Les Miles before becoming OC and head coach in waiting at FSU. Now in his sixth year at the helm, he's won at least ten games five times, a division title four times, the ACC three times, and a national championship. With his team in a New Year's Six game this year, he's made a BCS/NY6 bowl four times as well.
1B. Mark Dantonio
Dantonio hasn't won a national title yet, but the degree of difficulty at Michigan State is higher. Nonetheless, he's spent nine seasons there and won 11+ games five of the last six. He also wasn't a direct hire from a Saban staff, as he was DBs coach for him at Michigan State from 1995-99. After one more year in that role in 2000, he was Jim Tressel's first DC at Ohio State from 2001-03 (including the 14-0 team in 2002) and head coach at Cincinnati 2004-06. He's now made a BCS/NY6 bowl in three straight seasons, including the playoff this year. It's an amazing job no matter how you slice it.
3. Jim McElwain
The first direct hire from a Saban staff on the list, McElwain went from coordinating the 2011 national champions to resurrecting the Colorado State program. After going 4-8 in his first year in Fort Collins, he got to the postseason en route to an 8-6 finish his next. He then won ten games in his third season before taking the job at Florida. Once in Gainesville, he took the spare parts recruited for three different offenses and cobbled them together (along with a terrific defense) to make a ten game winner and the SEC East champ.
4. Jason Garrett
Garrett's first two years as a coach were as Saban's quarterbacks coach with the Miami Dolphins from 2005-06. He went right from that to being the Dallas Cowboys' offensive coordinator in 2007, and he made it up to head coach as interim in 2010 and full time in 2011. After going 8-8 in his first three full seasons, the Cowboys won 12 games and the NFC East a year ago. His team has fallen to just 4-8 right now in 2015, though.
5. Will Muschamp
He served as Saban's defensive coordinator from 2001-04 at LSU and in 2005 with the Dolphins before setting out on his own and becoming DC at Auburn and Texas. He was the Longhorns' head coach in waiting, but he got tired of waiting on Mack Brown to retire and took an offer from Florida. The program he inherited was "broken" in the previous head coach's terms, but he did manage to win 11 games and make the Sugar Bowl in his second year. He also went 4-8 in his third and could never put together a coherent offense to go along with his great defenses. His final record with UF was 28-21, but he has a chance to improve on that now with the Gamecocks.
6. Derek Dooley
He first coached tight ends and then running backs for Saban at LSU before coaching tight ends again for two years with the Dolphins. He then spent three years as head coach at Louisiana Tech, the latter two as athletics director as well. Doolander's time in Knoxville is probably best remembered more for colorful off-field stuff—from his mother's radio appearances to the orange pants to shower discipline—than the on-field happenings. Well, except of course for his 13-man defense against LSU and the bizarre Music City Bowl ending that ended up with the Vols losing and also begat the ten-second runoff rule. He went 17-20 in Ruston and 15-21 with UT. He both took over and left behind a mess in Knoxville.
7. Bobby Williams
Williams coached running backs at Michigan State from 1990-99, the final five of those years being for Saban. MSU promoted him to head coach after The Process went on to LSU, but it didn't last long. After going 5-6 in his first year, he did improve to 7-5 with a bowl win the next. However after a 3-6 start in 2002, the Spartans pulled the plug. He's been a Saban assistant ever since at LSU (2004), the Dolphins (2005-06), and Alabama (2008-present).
8. Mike Haywood
Saban retained Haywood as running backs coach off of Gerry DiNardo's staff, and he remained in the post through the 2002 season. He went on to coach running backs at Texas before becoming Charlie Weis's offensive coordinator at Notre Dame. Miami (OH) hired him as head coach, and he went from 1-11 in 2009 to 9-4 in 2010. He rates last on the list because of his very short time at Pitt. The Panthers hired him as head coach in mid-December of 2010, but he was arrested for felony domestic violence two weeks later on New Year's Eve. Pitt fired him, and he's been out of coaching since.
Two have been unqualified successes: Fisher and Dantonio. It's still early for McElwain, but he appears to be trending in the right direction too.
Things have been mixed for Garrett, but the NFL is a different beast with the draft and free agency versus the direct control over recruiting that college coaches have. Muschamp's time at Florida was also mixed, with a high high, a low low, and two middling seasons. It's mixed enough that he still managed to get the South Carolina job after only one year as a coordinator in between.
Dooley, Williams, and Haywood probably won't get another shot as head coaches like Muschamp did, though. Dooley is still young enough that a non-Power 5 program might bite on him, but that's about all I can see. Williams appears to be a career assistant at this point, while Haywood is out of football for reasons that have nothing to do with Saban.
Georgia is hoping that Kirby Smart will be like the guys in the first group, but two of them were offensive coordinators for Saban and the third proved himself on his own at Ohio State and Cincinnati. At eleven total seasons (one at LSU, one in Miami, and nine at Alabama), Smart is the longest serving Saban assistant of any on the list, but there is no correlation between time under Saban and success.
In other words, hiring Smart from Alabama is not much less a roll of the dice than hiring a coordinator from anywhere else. Nor, for that matter, is hiring Muschamp, depending on how much you think he learned from his first time around.