How old is "old" for Dancing with the Stars?

Fans of Dancing with the Stars have become adept at handicapping a star's chances to win the Mirror Ball Trophy. Older celebrities are presumed to be disadvantaged, but how old is "older"? Would you believe 38? Several celebrities have won DWTS in their mid-thirties, but there's been a notable gap after 37. From youngest to oldest, the winners' ages have been:

It appears that mostly very young athletes, young performers, mid-30's athletes, and early 50's pop culture icons have dominated the winner's list. The age 37 cut-off could be a fluke. Possibly, a Kristi Yamaguchi or Donald Driver could have won in their 40's . However, it's not just winners, but finalists who have been dominated by the 37 and under crowd. The historical percentages through 15 seasons are:

The disproportionate success of young stars is apparent, comprising over 80% of all finalists. The struggles of older stars also is apparent, with a finalists rate (16%) about one-third their overall participation rate (46%).  While performance generally declines with age, further analysis shows that males and females decline differently. Rounded to the nearest full place, their average placements (normalized on a scale of 1st place to 12th place) are:

The similar 5th place average of young males and young females suggests that they can compete directly with each other. Males' results decline progressively with age. Surprisingly, middle-aged females struggle for placement as much as senior males, but senior females compare to middle-aged males. Conceivably, these middle- and senior-aged groups could benefit from competing with each other, under age-adjusted rules.

Why middle-aged females have struggled so dramatically is unclear. As stated previously, young Athletes in their mid-thirties have done well. That raises the question whether not just age, but an interaction of job and age affects performance. Considering the seven job categories of stars that ABC identifies in their online fantasy casting forum, here are the averages of the various groups' normalized (1 to 12) placements, with the number of corresponding stars in parentheses:

Averages have been rounded to the nearest half place. If we assume that young stars have the highest potential placement, then their performance sets a "baseline" for each job category. The jobs are listed from the best to worst average placement for young stars, with bright yellow indicating an average of 5th place or better, and light gray indicating an average of 8th place or worse. (Shading indicates a weak average based on just 1 or 2 stars, while dark gray indicates an absence of stars.)  Overall, Actors, Athletes, and Singers have the highest baseline potential.  Because we know that males and females age differently, we can parse the numbers by gender:

Several things stand out. First, there has been a lack of middle-aged and senior Reality stars. The youth baseline indicates that Reality stars do "OK", so maybe over-37 Reality stars would do "OK".

Second, as poorly as middle-aged actresses have generally placed, senior actresses have placed much better. The senior actresses include winner Jennifer Grey and one-time finalist Kirstie Alley, as well as Susan Lucci, Jane Seymour, Florence Henderson, and Cloris Leachman . Nostalgia may have helped these women, along with a bit of train-wreck humor in Leachman's case. Among the middle-aged actresses, Lisa Rinna, Marlee Matlin, and Melissa Gilbert are among those who have done OK. Tatum O'Neal, Denise Richards, and Shannen Doherty are among those who haven't. (And there's Pamela Anderson, who has and who hasn't.)  Why middle-aged actresses fare so much worse than young actresses--a group that includes Kelly Monaco, Jennie Garth, Marissa Jaret Winokur, Shannon Elizabeth, and Melissa Joan Hart--is unclear, especially given the relatively greater fame of the middle-aged group. Nevertheless, their struggles contribute to the overall lack of success for middle-aged females.

Third, there have been many over-37 Others, but not so many over-37 Athletes. Given the high baseline average of young Athletes, this factor could explain the drop-off in performance by over-37 stars, especially female stars. Both the Other and Athlete job categories have notable sub-groups worth separating. It's general knowledge that Basketball, Boxing, and Tennis (BBT) athletes have done notoriously worse than other athletes. (This could be due to center of balance issues related to height or defensive crouch positions.)  And while Others are generally not performers, there is a distinction between Others who work in front of TV cameras like hosts and reporters, and Others who don't. Here are the averages for these subgroups:

The overall strength of non-BBT Athletes becomes clear: non-BBT Athletes have the highest youth baseline average of any group. We further see that male athletes continue to do well in their 40's, though none have won and only Jerry Rice has made the Finals. The absence of middle-aged female Athletes could partially explain why their placements drop off significantly. Or like female Actors, they too might struggle in middle-age and recover as seniors. Hopefully, we'll have the opportunity to learn which is the case. For the Others job category, the influence of TV exposure appears to make a difference. Certainly, seniors Jerry Springer and Nancy Grace appeared to benefit from their fanbases. However, the super-high success of very young Other-TV females could result from Derek and Maks having partnered all three (Brooke Burke, Maria Menounos, Erin Andrews). Additional data is needed to see whether this group reliably yields exceptional results

Comments

Having seen the disparity between young stars versus middle-aged and senior stars, we can ask, "Can the playing field be leveled?" Drawing attention to the problem can start conversation about why the disparity exists. Campaigning for more middle-aged and senior Athletes might help, especially female Athletes. The same might go for Reality stars and possibly Others. Suggesting reasonable adjustments to scoring criteria for various age groups can address the root of the problem:  That of having such an age-varied mix of stars compete directly against each other in the first place. Ultimately, advocating for a separation of age groups might be the best solution. Defining individual seasons as Under-40 Stars or Over-40 Stars should create fairer competitions. (Or Under-/Over-39 , if the semantics make the demo-sensitive producers happier.)

Simply drawing attention to the problem may not be enough. At best, it might spur them to cast more Jennifer Grey, Osmond, Kirstie Alley types with mega-fanbases, leaving most over 37 stars at a continuing disadvantage.  At worst, it might unfortunately lead the producers to manipulate a PC winner to prove a point, and then revert to the usual youth-dominated format.  Lasting format changes are needed. If it turns out that there's not enough concern about age disparity on "Dancing with the Stars", then anyone who does care can simply choose to support the older stars they like and feel deserve their vote. After all, the only criteria for "best dancer" or "deserving winner" that any viewer is obligated to vote for is their own.

Update

The new Season 16 cast addresses some of the holes mentioned above.  Namely, we have a senior Reality star (Lisa Vanderpump) and a senior Female Athlete (Dorothy Hamill).  There also are no 30-something stars, which sets the season up as something of a lab experiment in terms of how very young teens and 20-something dancers are perceived by fans and judges, versus how middle aged and senior dancers are perceived.  Should be interesting.