"Becoming a GM" only seems possible for people who reached master strength by their early teens. Some people have attained GM later in life, 30s, 40s and even older - but all GMs have been child prodigies and most - if not all - attain International Master in their teens or early twenties.

It's certainly rare, but it's not unheard of.

Mikhail Chigorin apparently learned the rules of chess at 16, but only really started playing at 27.

Gersz Salwe started playing around age 20, and apparently entered his first tournament at 36.

And in terms of blooming late, Oscar Shapiro and Bernard Friend became GMs in their 70s.

(Also, I don't see it stated anywhere that the prisoner was not an exceptionally-talented youth.)

Chigorin and Salwe were both born in the mid-1800s. With the prevalence of chess computers for training and studying, the amount of strength you need to play at a top level is much higher these days.

I don't think it is just the computers. The training environments and systems for learning advanced quite far without the engines. Kasparov didn't train with computers in his prime and he is still very strong by modern standards. More children were encouraged to pursue chess...in the 19th century many people (such as Paul Morphy) would consider a professional chess player in roughly the same social tier as a professional gambler. If you look at many of the games from that era it seems like only 20 people in the world even knew how to play chess.

Indeed, Morphy once said "The ability to play chess is the sign of a gentleman. The ability to play chess well is the sign of a wasted life".

On the other hand its never been easier to get that kind of information. It's probably easier than ever to reach Candidate Master (2000 Elo). GM, maybe harder, but definitely could see the argument otherwise.

The skill required for a particular ELO is relative to the strength of all the other players. More learning resources that are available to everyone can't provide a comparative advantage, which is what you need to move up. Part of the reason the Soviets dominated for so long is they had developed a training program that the rest of the world did not have access to.

> "Becoming a GM" only seems possible for people who reached master strength by their early teens.

Mostly, I think, because becoming a GM is a full-time job and you don't earn any money while doing it.

You need to go to a lot of tournaments around the world, continuously study to get prepared for opponents, and have enough money to fund it all.

So, you really have to want it as an adult and have nothing else that you would prefer to do.

It's plenty possible, but few have the desire to put in that much work as they get older. There are people who play at near-GM-level strength in tournaments reflected in their single tournament evaluations, but don't play enough to obtain 2500+ rating or score enough GM norms in major tournaments.

There's a even a guy from Russia who is 2550ish rating and isn't even an IM because he hasn't scored enough norms, and is 3000+ bullet/blitz on Chesscom, which is incredibly elite.

Someone picking up chess at age 25 could certainly become a GM. They just usually don't have the desire for it.

If it were possible it would have happened in the last 100 years. What people lack at the age of 25 (or even 17) is the neuroplasticity required to turn their brain into an analytical chess engine.

That's kinda true for most things in competitive arenas, right? Sports, chess, e gaming, etc. I hate it, but at mid life I'm way slower thinking than I was 20 years ago, there's no chance I could compete with young people on raw talent in many areas, I might win some online games because of superior strategy, but I'll never have the speed to beat young, experienced gamers.

I have always found gymnastics fascinating in this regard. Apparently you can only be good at it if you're a 15 year old girl!

It used to be even sooner, but the kids health ended up compromised too much as result of training. They changed rules so that the peek happens later.

You need a body with a low moment of inertia. I.e. short.

I don’t think it’s actually correct that all GMs were child prodigies.

At least since the 20th century I haven't been able to find an exception. Even GMs who did not get their GM titles until late in life were very strong players as children. For example Ben Finegold did not get his last norm to become GM until he was 40, but he was a USCF master at age 14. All the other stories I've seen are similar. I've also yet been unable to find more than two or three people who started playing seriously after age 25 and ever broke 2000 FIDE.