So, while I was bored on a Saturday morning, I decided to research what a ringer on Strictly actually is and who falls into this category.
There is this misconception on DS that "so-so always gets duffers, while so-so always gets ringers."
The truth is, there is more to it than that.
I'm going to analyse all the well known past pros (e.g. Darren, Lilia, Matt C) and all the current pros.
I will start with the female pros......

So, lets start.
There are 7 different types of ringers:
DANCE EXPERIENCE RINGERS:
Level 1- Done lots of dance in the past, learned choreography, more than light training or dance classes until 12 years old.
Level 2- Your typical Girl or Boybander. Probably some light training and plenty of experience in learning simple choreography. Usually has rhythm.
Level 3- Actor or Model. For Actors, they fall into this category if they are below 40. If not, that reduces ringer experience. Models also have to learn things such as posture and no doubt have some experience as well.
FANBASE RINGERS:
Level 1- Very popular and inside the voting demo for SCD.
Level 2- Very popular but not exactly inside the voting demo for SCD.
Level 3- Well known, but known for being controversial and in the news often. Could be popular but a degree of uncertainty
DAR:
Dual Attribute Ringer- Dance Experience AND Fanbase. Only 3 celebs in SCD history fit into this category.....

With the female pros, it is difficult as men are less likely to have dance experience.
But that's not to say that they are all given a really rough deal.
Lets start.
Camilla (Series 1-5, Winner of Series 6)- In S1 had David Dickinson- duffer, but after him she's done quite well. Roger Black wasn't a dancer but an Olympian so I gave him a Level 1 fanbase as he got to the Q. Finals. Couldn't find anything to suggest James Martin was a ringer, but I do know who he is as I occasionally watch Saturday Kitchen. Ray Fearon was an actor and a good dancer so I gave him a Level 3 experience, then Gethin was a Level 1 fanbase and Tom was the same as Ray, Level 3 experience.

Erin (Series 1-10)- Erin wasn't too lucky with partners. Martin Offiah wasn't a ringer, then Julian Clary. He got to the finals over better dancers so he was an obvious Level 1 fanbase and then Colin Jackson was also a Level 1 fanbase as an Olympian. Since then, she didn't have the luck of the draw. On paper, Austin Healey wasn't a contender, and he did really well so that was good but post- Austin, she had fairly mediocre dancers until she left to start a family after Series 10.

Lilia (Series 2,4-7, Winner of Series 3)- Lilia never had an actual ringer despite an excellent record in her first few years. 4th, 1st and 2nd. Aled wasn't a ringer, Darren and Matt both got 19 in their first week so it was down to her teaching and choreographing that got those 3 so far into the competition. Post- Matt, she got a bunch of no-hopers that even she couldn't turn into dancers.

Karen Hardy (Series 3, 5, 6, Winner of Series 4)- Mark R wasn't a complete favourite at the start and he was a great surprise and other than Mark, Karen had duffers. Bill was OK but Brian and Gary were both duffers.

Flavia (Series 4-9, Winner of Series 10)- For those who say Flav always gets duffers, I am about to prove you wrong! Fair enough, she started hard with Jimmy Tarbuck but then she got Matt Di Angelo, a young actor who got to the finals so was a clear Level 3 Experience.
Phil Daniels wasn't great but he wasn't that bad to be out first and then she had Craig Kelly, who was a difficult one but post- Craig, she did well. She had Jimi, her now husband who could dance and was another Level 3 experience, he was just a shock exit so Widdy could get to the Q. Finals. She had Russell and while he was a bit of a Comedy Act, he wasn't a terrible dancer, got quite far and had a fanbase so he was a Level 2 Fanbase and then in her last series had Louis Smith, who I classified as the only male contestant ever in SCD to be a Dual Attributes Ringer. He was a gymnast, had certainly done ballet, fresh out the Olympics in London 2012, great fanbase and she picked up the trophy. Flavia did have her fair share of contenders and I'm glad both her and Vincent went out on a high.

Ola (Series 4-6, 8-13, Winner of Series 7)- Yes, Ola won, but Chris wasn't a contender and it was their partnership and lack of competition that year that got them the trophy. She's just mostly had middlers and then Paul Daniels who was a duffer. Spoony could have been good but he didn't get a fair chance and then she had Kenny, who could do ballroom and not Latin, Andrew Castle who was mediocre along with a height mismatch, Chris, Paul and Robbie Savage who was another Kenny dance wise. She managed to get him to the QF even though he was rubbish at Latin but he was known as a controversial character so I put him down as a Level 3 fanbase. Then, she had Ashley, who was her only contender- But he had a day job and a newborn baby so he was too burned out by the end. Level 3 Experience Ringer. Then, Steve who was another Middler and Iwan, who no one expected to be a total dud who was first out and after Iwan she quit the show. Best wishes for her.

Kristina (Series 6-13)- Kristina started off with 2 duffers and I thought in 2010, it would be a third time lucky for her, but no such luck and I felt really sorry for her when she and Goldie were out first in Series 8, especially since he wasn't THAT bad. But fourth time lucky with Jason Donovan, he didn't do much for the public but was a brilliant dancer and it was obvious he had plenty of experience and he was a Level 1 Experience Ringer.
Then she had Colin, who was OK but there was a height mismatch there, and then she had Ben, another middler and we know what happened there.
In 2014, she had Simon Webbe, a boybander so an automatic Level 2 Experience and he was a Runner Up. He wasn't great until the AT in Blackpool which is when he really came into his shell but then she had Daniel O'Donnell. I thought that he would be terrible, dull but would be kept in via fanbase.
No, he was a OK dancer, came across quite well but his fans didn't vote and he was out Week 4. I put him down as a Level 2 Fanbase Ringer. Then, Kristina left the show as her and Ben are expecting a baby. All the best!

I get where your coming from and since your relatively new on here welcome

There will always be people with dancing experience and people without any. The showbizz personalities will always be some kind of dance trained - the can't be actors or singers without it, that can they.
But the show is not just down to dancing skills it is also to personalities (1) and partnerships (2). So there are more ingredients to your chances to go further that training experience.
And before anything else it is a show.
I could start with the judges credentials. How many of them are Ballroom champions? Yes, exactly.

Tom Chambers was a level 1 ringer. It would seem he had quite extensive dance training and his CV since SCD supports this. James Martin got his Saturday Show after SCD raised his profile so I would suggest he was not a ringer.

No he wasn't his ballroom was average nothing special and his latin was a disaster completely dreadful

What you thought of his ballroom dancing has no bearing on his dance experience and training. I don't agree with your assessment of his dancing on SCD but then again you think Anton's the bees knees, so less said.