Welcome to the Second Annual San Francisco 49ers Head Coaching Search! With 2015 49ers football reaching its merciful end, and Jim Tomsula relieved of his head coaching duties, our attention (or perhaps more accurately, my attention) will now turn to San Francisco’s two biggest offseason priorities: finding its head coach and quarterback of the future.

Thanks to the disaster that has been this franchise over the past calendar year, we’re a step ahead of the curve for priority No. 1, having done a significant amount of legwork during the 49ers’ last head coaching search. Last January, I researched NFL head coaching tenures since 1994, when the salary cap was instituted, in attempt to identify some measurable traits shared by the league’s best coaches at the time they were hired.

The results of that research, and most of the other related research that I’ve seen, were conclusive, but not in the way you’d hope; there is no magic formula for finding the next Bill Belichick. That shouldn’t come as a surprise given how often head coaches fail to live up to expectations. Nearly two-thirds of the 152 head coaches hired in that time frame did not produce a winning record over their tenure. And the one-third that do find success come from myriad coaching backgrounds and experiences.

In fact, if you learn only one thing over the course of this search, let it be this: No one knows anything about hiring NFL head coaches. The success rate of NFL franchises finding the right guy for the job speaks for itself, and if the people whose jobs are on the line know little about what makes a head coach successful, outsiders like us know even less.

That said, there were some useful takeaways from that research that we can use to help narrow our list of candidates, even if it falls short of providing a clear blueprint for a home run hire. Before we get to that list of top candidates, let’s examine some of the traits I researched a bit further and weed out some names in the process.

Below is a chart highlighting a few of the different splits I looked at and how those coaches fared as measured by Pythagorean win percentage, which is based on point differential and provides a more accurate measure of team performance than straight winning percentage.

Position coaches and internal hires have the worst performance of any split I looked at. Jim Tomsula was the rare candidate who fell into both buckets, joining infamous hires such as Raheem Morris (Bucs), Tom Cable (Raiders), Mike Singletary (49ers), and Mike Tice (Vikings) who could only manage to hang "top 10 pick" banners. Luckily, it appears Trent Baalke will be focusing his search outside of the organization this time around, allowing us to rule out candidates such as Eric Mangini, Tony Sparano, and Jason Tarver.

There aren’t too many position coaches on the league-wide radar from what I’ve seen, but Bills running backs coach Anthony Lynn and Seahawks offensive line coach Tom Cable are names I’ve seen mentioned that Baalke should ignore. There’s simply too much evidence suggesting coaches can’t successfully make that jump to warrant paying significant attention to these candidates.

First-time head coaches don’t fall in the clear stay-away bucket, but they have fared worse than coaches who are on their second or third go running a team. There’s almost certainly some survival bias influencing those numbers, as most coaches who are given multiple head coaching jobs have shown some level of promise while the worst of the bunch never get another opportunity. Many first-time head coaches, looking for any chance to grab one of just 32 jobs, often end up in awful situations with a talent-poor roster and dysfunctional front office (Hey, that sounds familiar!). Coaches looking for their second or third head coaching jobs are likely more willing to wait for a better situation to roll around after getting run out of town at their first stop, leading to more success.

So while hot candidates such as Bears offensive coordinator Adam Gase, Lions defensive coordinator Teryl Austin, Panthers defensive coordinator Sean McDermott, and Seahawks offensive coordinator Darrell Bevell, among others, will grab plenty of headlines in the coming weeks, I’m crossing them off my list. Several of them might very well go on to become quality NFL head coaches, however, I don’t believe this organization currently provides an environment conducive to a first-time head coach finding success. I’d rather hitch my wagon to a candidate looking for job No. 2, who has (presumably) been able to learn from the mistakes he made at his first stop and make necessary adjustments.

I’m also excluding college coaches from my list. This one has nothing to do with performance — thanks to recent successes like Jim Harbaugh and Pete Carroll, college coaches actually have the highest Pythagorean win percentage of any split I looked at — but rather that the top college candidates all appear content to keep living that cozy college life and are unlikely to be lured to the NFL, at least this offseason.

The other major factor I considered was whether the coach had an offensive or defensive background. Offensive coaches (0.498 Pythagorean win percentage) hold a slight edge over their defensive counterparts (0.486), and the gap widens slightly if you narrow in on the past decade. Despite that advantage, there’s not enough evidence to suggest teams should ignore well-qualified defensive coaches.

Bill Belichick and Tony Dungy have the two highest Pythagorean win percentages in our sample, and more recently hired Todd Bowles and Mike Zimmer have started their tenures off on a positive note. Teams can find the right man for the job going either direction here. Ultimately, the construction of the roster is the biggest factor in determining whether an offensive or defensive coach is a better fit for the team.

In the case of the 49ers, I don’t think it will be controversial to say they would likely benefit from an offensive-minded head coach, particularly one capable of developing a young quarterback. San Francisco is lacking star power across the roster, but with promising young players like Aaron Lynch, Arik Armstead, Jimmie Ward, and Jaquiski Tartt on defense there’s a bit more to build around on that side of the ball.

Based on the data above, and the current construction of the roster, four names stand out above the rest as the candidates Baalke & Co. should be focusing on. This is hardly some ground-breaking list with unearthed candidates no one else is discussing, rather it’s a pared down version of the same list you’ve seen everywhere else.

There are a lot of shared characteristics — all four candidates are currently looking for NFL head coaching job No. 2, come from offensive backgrounds, and (barring one) have at least 15 years of NFL coaching experience. They’re not without flaws, of course, and you could raise many of the same concerns about each candidate. But each coach has a strong Xs-and-Os background and was held in high-enough regard at some point in their career to believe there’s a reasonable chance they’ll be better at their second stop.

I’ll be looking at several, if not all depending on the timing of the hire, of these candidates more in-depth in the coming days. For now, here are those four candidates, in alphabetical order, along with some brief background info.

Hue Jackson

Age: 50

NFL Experience: 15 years

Current (or previous) Job: Bengals offensive coordinator

Jackson has served as a position coach for each of the major skill position groups (running backs, wide receivers, quarterbacks) in addition to short stints as an offensive coordinator with four different teams. His head coaching experience, of course, came in Oakland where he led the Raiders to an 8–8 in his one season at the helm.

There are several indications that Jackson is near the top of the 49ers’ list. San Francisco has reportedly requested permission to interview Jackson already, and Kyle McLorg reported that Jackson is Baalke’s guy, with the two having worked together in Washington.

Chip Kelly

Age: 52

NFL Experience: 3 years

Current (or previous) Job: Eagles head coach

Kelly is the most polarizing name on this list. His tenure as the Eagles head coach, his first job in the NFL, came to an end under less-than-ideal circumstances and many are ready for him to "take his act back to college." However, there are a lot of misconceptions about Kelly’s offense floating around out there and there’s plenty of reason to believe Kelly is a guy who will make the necessary adjustments and be more successful at his next stop. More to come here.

Josh McDaniels

Age: 39

NFL Experience: 15 years

Current (or previous) Job: Patriots offensive coordinator

I made the case for and against McDaniels a year ago, and those same points remain relevant a year later.

Sean Payton

Age: 52

NFL Experience: 18 years

Current (or previous) Job: Saints head coach

Payton is the biggest fish on the list, and the most recent rumors at the time of this writing indicate Payton is choosing between the 49ers and staying in New Orleans.

Having spent nine seasons as the Saints head coach and winning a Super Bowl in the process, Payton’s résumé is the most formidable on this list and we know more about him than any of the three other candidates. While any of these candidates would be significant upgrades over Tomsula and his staff, Payton is the one guy who could add a level of credibility back to this organization before he even coaches his first game in San Francisco.