Sherlock
Dominant Te: Mycroft is all about order and organization. He evidently “is the British government” and has a large compendium of people to whom he delegates tasks. His plans tend to be expansive, detailed and always quickly put into action. He hates it when Sherlock’s snooping interfere with any of the long-term plans he’s put into place and comes to his apartment directly tell him to stop. He likes to be in control of everything, and that often includes taking charge of his brother’s life as well (much to Sherlock’s loathing). Mycroft dislikes his emotions and seems almost to take pride in dismissing “sentiment.” He pretendsnot to love, even when it comes to family. Mycroft doesn’t only feel the need to organize the world, but feels the same compulsion toward his environment –enough so that Sherlock deliberately messes things up just to annoy his “OCD” side.
Auxiliary Si: Mycroft is continually looking at the past and even has a difficult time recognizing when Sherlock has changed so that when he looks a Sherlock, he sees him as the same frightened little boy that he saw growing up. In general, Mycroft prefers to observe tradition, and as a result, he has an extremely difficult time understanding his brother’s radical behavior. Mycroft is much more of a traditional than Sherlock is, and he tends to view Sherlock’s non-conformity as childishness. Mycroft doesn’t want his parents to refer to him by nick-names, but somewhat rudely asks his mother to “struggle all the way to the end” of his name.
Tertiary Ne: Mycroft isn’t particularly intuitive, and when he isn’t observing logical evidence, he tends to come to incorrect assumptions about people –thus, ease understanding John and complete inability to understand Sherlock. Though he’s known Sherlock for years, admits that he still finds him unpredictable. With this in mind, he plans for anything, making sure to have all his exits covered in case of disaster. Mycroft finds Sherlock’s games childish because he would rather devote his time to more serious endeavors. Mycroft is always viewing everything in terms of the big-picture, and is often frustrated when Sherlock deviates to follow a trail of details.
Inferior Fi: Mycroft likes to pretend that he isn’t emotionally attached to Sherlock, yet through his actions we see that this isn’t the case at all. He feels the need to monitor and protect him, but does so in a controlling sort of way, such that Sherlock shuts him out. Mycroft is good at hiding his emotions, to the point that takes a drugged drink of punch to get him to openly share his feelings with Sherlock. He doesn’t think that he needs other people in his life (insisting that he’s not lonely). His work is primarily aimed at benefiting the world at large, but he often places more importance on this work than he does trying to secure a true relationship with his brother.
Most people seem to see Mycroft as either an INTP, ISTJ or INTJ, however, I differ. If you’re wondering about the I vs E thing, just remember that not all extraverts are social, just like not all introverts are recluses.
Mycroft just happens to show far more Te than he does Si.
The Book Addict's Guide to MBTI: 
This isn’t right at all. Mycroft always lives alone and isolated. As @ENTP pointed out, he is a wizard at prediction and he is extremely strategic. ESTJ’s aren’t big-picture thinkers who can run an entire country by themselves. Mycroft is definitely an INTJ.
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You don’t have to be big-picture oriented to run large organisations. You only have to be controlling and/or extremely task oriented.
Mycroft’s ability to run a country has little to do with Ni, and more to do with Te.
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Well, we all know that Mycroft is slightly smarter than Sherlock. Isn’t it extremely unlikely that an ESTJ has IQ superior to an INTJ(I believe Sherlock is INTP though)? Also, Fi is not the inferior function of Mycroft.
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Not necessarily. I usually think my ESTJ mum has a much better talent for problem solving than my ENTJ grandpa. “Smarter” is not defined by IQ or personality type.
If your evidence was not reliant on stereotypes and misinformation, then I would reconsider Mycroft’s typing, but so far, the research I’ve put into the project still checks out logically in the face of your comments.
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Holmes is ISTP. There’s a lot of misinformation out there. Here’s a very good write-up to explain.
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Let me justify my typing of the Holmes brothers.
INTP’s are driven to satisfy their thirst for knowledge and need to use it. They are satisfied with their jobs as long as it intellectually engages them and they’re not much bothered if their job is doing any justice to their intelligence if it’s providing them the stimulation . Primary function – Ti. That fits Sherlock perfectly. “Sherlock has the mind of a scientist or a philosopher (or ‘an intelligence agent’, etc.), yet he chooses to be a detective.”
INTJ’s are driven to improve things around them or make an impact. They want to do something of greater significance to the society. And even though they have the thirst, they care only about what actually matters. Thinking is used to arrive at conclusions but that unquenchable thirst (like Ti) is absent. They don’t go out of their way to completely clarify everything as long as they get the idea (Ni and Te). And that fits Mycroft. “I have solved it only in my mind. I need you for the … legwork”.
Keeping interpretations about the characters, aren’t my descriptions of the two types correct?
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Unfortunately, I think you need to do some reading about the difference between Te and Ti.
It is not ONLY Ti users that have an unquenchable thirst for knowledge. People of all types are capable of that. That…among other things.
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In socionics and even in MBTI sense this typing is a complete fail. ESTJs are super bad at Ni. Mycroft is wizard at prediction. He has very keen sense on Ni.
INTJ might be the type for him.
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ESTJs predict the future too, but based on past experience rather than by looking at patterns
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