What is the difference in mindset or technique that really makes the difference between an expert and a master? I am trying to decide whether or not to start playing again and try to make that leap.
To become a master from expert, I think having a mentor is the most important factor. I know personaly a chess player who got elo rating from 2000 to 2300 with a well-known mentor from Switzerland.
Moreover, I think knowing theory and playing against very good players (2400+) can really help.
I would definitely invest in a chess teacher, it will be worth your while, If you are poor this doesn't work, sorry.
My highest USCF rating was 2302. The biggest difference I see between masters and experts is the defensive resistance and resourcefulness that masters show during the game. They don't just let you beat them the first time something goes wrong! You have to beat them over and over again during the game in order to finally win.
Yes, masters have better all around openings, tactical vision, technique etc. But you really have to hate to lose in order to be a master.
I once wrote a blog post about becoming a master; several themes seemed crucial:
- Playing regularly in tournaments
- Doing it while you are young
- Keeping in mind that the effort required per 100 points of ELO increases the higher you go. That applies "across the board" - endgames, openings, etc.
- Having a "mentor" (not the same as "coach")
If you have not played for while though, you might first want to make sure you are still as good as you were before stopping.
I'm not sure I'd agree that you need to start young. Larry Kaufman became a GM in 2008, at the age of 61. But you will definitely have to put in the hours and the effort. Some of the distinctives of higher level mastery in chess are:
Probably the most time-consuming skill to acquire is pattern recognition. It has been estimated in cognitive research that GM's know nearly 100,000 patterns. This requires focus, patient and diligent memorization, and gaining experience with new patterns from playing.
Intuition is the foundation for a sense of danger; you don't want to make moves intuitively, but you need to sense when your opponent might be able to prepare a threat or even a package of multiple threats.
Conversely, you need to be able to sense when there must be an opportunity for a combination on the board, even though you can't see it yet. It's as if the deployment of pieces or the pawn structure is whispering to you, but you can't quite hear what they're saying. The highest level of this kind of expert judgment takes 1,000's of hours of experience to acquire, but it starts small and builds.
A master is also able to allocate their thinking effort (and time) much more productively than an ordinary club player. They know when to calculate a tree of variations in depth, and when to make a move on principle without any deep analysis. This helps them conserve their energy, and increases their stamina. Carlsen and others are rightly famous for being able to think as well in the 7th hour of a game as they did in the 1st.
For more guidance on becoming a Chess Master, I recommend Andrew Soltis' What it Takes to Become a Chess Master, from Batsford Publishing.
It's not "technique" that separates an expert from a master; it's "orientation." Unless you plan to make a living e.g. teaching chess, or make it the dominant part of your life, I advise you not to aspire to be a master.
An "expert" in chess (or other games) is someone who has a sound overall knowledge of the game, plays well, and makes very few "obvious" mistakes. This kind of person is at the top of "amateur" levels. In Academia, this might be the equivalent of a "Masters" degree.
A "master" is a professional-caliber chessplayer. That is, someone whose games (even losses) are of high enough quality to contribute to the "literature." To be a master, you have to be "creative" and able to outthink and out create other masters. It's like being a "PhD" in the field of chess. This is only for the most dedicated and skilled practitioners.
I knew two guys from high school. One was the champion of our chess league. Now in his 50s, he was rated about 2175 (when I looked him up on the internet). The other was a "varsity" football player, drafted by a professional team out of Penn State--and was soon cut from the roster. Both men were on the border between "expert" and "master," and they illustrate what it takes to get there. More to the point, they represent the best people in their respective fields that "average" people (outside their fields) are likely to get to know. "Better" players travel in rarefied circles confined to their field.