Same MBTI compatibility scores 76 and 77: why identical couples aren't number one
Same MBTI compatibility: three axes are maxed out, yet two introverts score 76, joint 17th (16 tied), and two extraverts 77, joint 9th (8 tied). A recalculated table shows why energy 62 vs 66 decides it.
SCHROE Editors
At eleven on a Thursday night, the shower ran cold. It was the first night this autumn that the temperature had dropped into single digits. Jiho walked out to the living room wrapped in a towel and took a photo of the error code on the boiler panel. Seoyeon, on the sofa, already had the building management app open. Both of them are INFPs.
"The repair center takes calls 24 hours," Seoyeon said, holding up her phone. "Oh, right," Jiho said, nodding.
And then neither of them moved. Seoyeon typed three lines into the support chat and deleted them. Jiho searched the error code and read four blog posts. Nobody said "I'll do it," and nobody said "Could you do it?" They each knew exactly how much the other hated making phone calls. In the end they boiled the electric kettle three times, filled a basin, and washed with that. Oddly, it didn't feel bad. Crouching together to get the water temperature right was actually a little funny.
The next morning, the call still hadn't been made. When Seoyeon messaged at lunch, "Can the technician come this evening?", Jiho finally realized that each of them had half believed the other had already called.
On SCHROE (schroe.kr), INFP with INFP scores 76. Two people who share all four letters, and they land joint 17th of 136 pairs, one of 16 pairs tied at 76. If two people understand each other this well, why aren't they at the top? This piece follows the order of the score calculation to answer that.
Same types already max out three of the four axes
SCHROE's MBTI compatibility score multiplies four axis scores by fixed weights and adds them up. The formula sits on line 223 of src/data/mbtiCompatibilityScores.js in deploy 6760abe0: conversation code (S/N) 35%, decision style (T/F) 25%, daily rhythm (J/P) 20%, energy balance (E/I) 20%. Add, round, done. No bonus points go in.
Each axis is scored by whether the two people share that letter. For a same-type couple all four letters match, so the math gets very simple.
| Axis | Weight | Two introverts: axis score | Share of overall | Two extraverts: axis score | Share of overall | |---|---|---|---|---|---| | Conversation code (S/N) | 35% | 84 | 29.4 | 84 | 29.4 | | Decision style (T/F) | 25% | 74 | 18.5 | 74 | 18.5 | | Daily rhythm (J/P) | 20% | 78 | 15.6 | 78 | 15.6 | | Energy balance (E/I) | 20% | 62 | 12.4 | 66 | 13.2 | | Total | | | 75.9 → 76 | | 76.7 → 77 | | Rank of 136 | | | joint 17th (16 pairs tied) | | joint 9th (8 pairs tied) |
Conversation 84 (code L78-84), decision 74 (L86-92) and rhythm 78 (L94-100) are the highest marks each of those axes can give, because the letter is shared. So the top three rows are identical for introverts and extraverts. Together they come to 63.5 points, and for a same-type pair that part is already maxed out.
Only the bottom row changes. Energy balance is defined at L102-108: two introverts of the same type get 62, two extraverts get 66. Four points times 20% is 0.8. After rounding, 75.9 and 76.7 become 76 and 77, and that one point is the difference between joint 17th (16 pairs tied) and joint 9th (8 pairs tied).
The two bars are almost the same length. The first three segments match exactly; only the energy segment at the end is slightly different. But past the end of both bars there is still empty room. The highest score any of the 136 pairs reaches is 79, and same-type couples fall two or three points short of it either way.
Why the energy axis pays less for being the same
Right above the energy function there is a short comment: "E/I: different means complementary." On this one axis, the code rates different letters above matching ones. The other three axes give their top mark for a match; energy runs the other way. An E with an I gets 76 when they share S/N, and 72 even when they don't. Both are higher than the 62 or 66 a same-type pair gets.
For comparison, in one line: INFP×ENFP, which splits only on energy and shares the other three letters, scores 79 and is joint 1st (8 pairs tied).
Why would difference pay off on energy? Conversation code and decision style are closer to speaking the same language. When you argue from the same kind of evidence and choose by the same standard, there is less friction. Energy is different. It is less a language than a set of roles: connecting with the outside world, meeting people and handling unfamiliar tasks first, or protecting quiet time for the two of you. When one person takes the outside and the other takes the inside, those roles split up on their own.
Jiho and Seoyeon's boiler was exactly that gap. They read each other very well. That is why each knew the other hated calls too, and why neither could hand the job over. The deeper the understanding, the emptier the hand that reaches outside. The 62 for two introverts isn't a score for a bad relationship. It is closer to a score for two people who rest on the same side, so nobody is assigned to open the door to the outside.
62 versus 66: why do two extraverts get four more points?
The code comments don't say why two extraverts get four points more than two introverts. So from here on, this is one way to read the numbers.
Two extraverts have two hands reaching outward. When someone has to make a call, talk first in a shop they've never been to, or reply to an invitation, either of them steps up easily. On the night the boiler broke, an extravert couple would probably already have one person on the phone. The empty role on this axis is smaller than it is for two introverts.
Instead, two extraverts get the opposite gap. On Saturday morning one has said yes to a college reunion and the other to an after-party for a coworker's wedding. Sunday there is an exhibition they planned to see together, and in the evening a couple they know is coming over. On Monday morning both turn off their alarms at the same moment and say, "Why was the weekend so tiring?" Neither of them said, "Let's just stay home this week." Both draw energy from being out, so the role of calling for rest is empty.
Put the two gaps side by side and the four points start to make sense. When nobody connects to the outside, daily life stalls: the boiler stays broken, forms don't get filed, appointments don't get booked. When nobody calls for rest, life keeps moving but both people wear out. The code weighs the first gap a little more heavily. Even so, 66 for two extraverts is still below the 72 or 76 an E and I get together. Either way, the code assumes that two people with the same energy leave one role unfilled.
Placing same types among all 136 pairs
Put the 16 same-type pairs on the distribution of all 136 pairs and they land in exactly two places. The eight extravert pairs all score 77; the eight introvert pairs all score 76.
The code's ranking function (L162-176) counts how many pairs score higher and adds one, so ties share a rank. At 77, 8 pairs are joint 9th, and all eight are extravert same-type pairs. At 76, 16 pairs are joint 17th: eight introvert same-type pairs, plus eight pairs like INTJ×ENFJ that gain on energy but split on decision style (T/F). Nothing scores above 79.
Seen this way, the place of same-type couples is clear: the second and third score steps from the top, well inside the upper group. But the top step is out of reach by design. The moment all four letters match, the energy axis can't give its top mark. So "identical means the best match" doesn't hold inside this formula. Identical means top marks for conversation, decision and rhythm, and no room for energy to complement.
Naming the empty role
What a same-type couple can do is agree in advance on the role the energy axis leaves empty. The score in the formula won't change, but the gap it points to can be filled in daily life.
The week after the boiler, Jiho and Seoyeon stuck a note next to the fridge titled "Outside duty." On it went phone calls, booking visits, returning parcels, and questions for building management. Jiho takes odd months, Seoyeon takes even months. However annoying it is, that month's calls belong to that person. They both still hate the phone, but they no longer push "Who's going to do it?" back a day at a time. A gap that came from understanding each other too well got filled with a simple rule about whose turn it is.
For an extravert couple, it runs the other way: a "rest duty." Twice a month, whoever has rest duty gets the right to turn down every invitation for both of them. For two people who recharge by going out, suggesting a quiet day always feels like a loss, so it only gets said when someone officially owns the job.
Either way the point is the same. The weak spot of a same-type couple isn't that they don't understand each other. It is that they're so alike that one role never gets assigned to anyone. Give that role a name and a rotation, and daily life fills in the few points the formula leaves empty.
Reading 76 and 77 again
Same MBTI compatibility isn't "identical is best," and it isn't "identical is boring." The formula says something narrower. Three of the four axes are already at their top mark, and the one left, energy, gets no complement because the letter is shared. On that axis two introverts get 62 and two extraverts get 66, which splits them into joint 17th (16 pairs tied) and joint 9th (8 pairs tied).
Jiho and Seoyeon's boiler was fixed on Friday evening. In the end Seoyeon made the call, and when she hung up, what she said was, "Next month is you." Jiho laughed and wrote his name on the note by the fridge ahead of time.
You can check the scores and axis breakdowns for all 16 types on MBTI compatibility.