Stuck at 161: the five misses that separate 161 from 170

If you’ve been sitting at 160 to 163 for two or three months while your practice volume keeps climbing, the problem is almost never effort and almost never question-type knowledge. It is five specific misses that look different on the page and are the same thing underneath, and none of them get fixed by drilling more of what you’re already drilling. This guide names them, with an original example of each, and gives you the check to run on your own wrong answers.

Here is the arithmetic of the plateau. At 161 you are missing roughly 15 to 18 questions out of about 75 scored (the scale moves a little by form; LSAC publishes it with each PrepTest at lsac.org). At 170 you miss roughly 7 to 9. The gap is about nine questions, spread across two logical reasoning sections and one reading comprehension section. Nine questions is not a knowledge gap. It is a perception gap, and perception gaps have a short list of causes.

Miss 1: treating a necessary assumption as a sufficient one

This is the biggest leak at 161, and it is why “assumption” questions feel inconsistent to you. There are two different questions hiding under that word. A sufficient-assumption question asks for a statement that, if added, makes the conclusion follow with certainty. A necessary-assumption question asks for something the argument cannot survive without. Students at 161 pick the strong, conclusion-guaranteeing answer on both, and on the necessary question that answer is often wrong because it goes further than the argument needs.

The fix is the negation test, used mechanically for two weeks. Negate each answer choice. If the negated version destroys the argument, the original is necessary. Negating (A) gives “not all staff will commute by bus,” and the argument survives fine. Negating (B) gives “no late staff are late because of transportation,” and the argument dies. Run it every time.

Check your blind review for the word “requires” or “depends.” Count your misses there.

Miss 2: the scope shift

A scope shift is when the premise is about one thing and the conclusion is about a slightly different thing, and the shift is carried by a noun or an adjective you read past. These are the misses you can’t explain afterward: you reread the stimulus and it still looks fine. It looks fine because the shift is in the words, not the logic.

The habit that catches scope shifts is reading the conclusion first and underlining its subject and its key quality, then going back to the premises and asking whether they are about exactly that subject and exactly that quality. “Residents” versus “attendees.” “Reduces costs” versus “is profitable.” “Is more popular” versus “is better.” The shift is always a substitution of one for the other.

Miss 3: conditional logic, specifically the converse

You know what a conditional is. The misses at 161 are not about diagramming “if A then B.” They are about four specific triggers that reverse the arrow, and about the converse, which is the single most common wrong-answer pattern in inference and parallel-reasoning questions.

The triggers:

• “Only if” introduces the necessary condition, not the sufficient one. “You may enter only if you have a ticket” is Enter → Ticket, not Ticket → Enter.
• “Unless” means “if not.” “The game is played unless it rains” is Not Rain → Played, equivalently Not Played → Rain.
• “Requires,” “depends on,” “is essential for” all point to the necessary side.
• “No A is B” is A → Not B, and the contrapositive is B → Not A. Both are valid. “Some A are not B” tells you nothing conditional at all.

The fix is boring and works. Diagram every conditional you meet for two weeks, write the contrapositive under it, and before choosing an answer on an inference question, ask whether the answer is the contrapositive (fine) or the converse (wrong). Students who do this stop missing conditional questions in about ten days. It is the most fixable of the five.

Miss 4: degree and quantity

A strengthen answer that says “always” when the argument only needs “sometimes.” A flaw answer that says the argument “assumes everyone” when the argument only assumed “most.” A must-be-true answer built on “some” when the stimulus only supports “at least one in a specific case.” These are degree misses, and at 161 they are nearly as common as scope shifts.

The LSAT writes answer choices that are right in direction and wrong in strength, because that is the hardest thing to notice under time. The words that carry degree are short and easy to skim: all, most, some, many, few, never, always, likely, certain, tends to, can, must.

Circle the quantifier in the conclusion. Then circle it in each answer.

Miss 5: the true-but-useless answer

This is the miss students resist most, because the answer they picked was correct about the world. It just did nothing to the argument. On strengthen, weaken and evaluate questions, roughly one wrong answer per question is a statement that is plausible, relevant-sounding and completely inert, and it attracts students who are reading the answers as facts rather than as moves.

The fix is to prephrase before you read the choices. If you know you’re looking for “an alternative cause for that month’s jump,” (B) jumps out and (C) looks like what it is, background noise. Students who read the five choices cold spend their time evaluating truth instead of effect. The guide on prephrasing covers the method in depth.

How the five show up in your blind review

Blind review is the step most self-studiers skip or do badly, and it is where the plateau breaks. The method: after a proctored section, before checking answers, go back through every question you flagged or felt unsure about and rework it untimed, writing a second answer if you change your mind. Then check. Then, for every miss, write the cause in one of the five categories above, or a sixth category called “I can’t name it.”

After two or three tests you’ll have a tally. Ours typically look lopsided, with two categories carrying most of the misses. That is good news, because two categories are a two-week project. The sixth category is the one to pay attention to: a question you cannot categorize after an untimed rework is a question built on a distinction you have never seen. Those are the ones a tutor earns their fee on, because you can’t teach yourself a thing you can’t see.

What the fix looks like week to week

Suppose the tally shows necessary-versus-sufficient and conditional logic carrying twelve of your sixteen misses. Week one is the negation test on every assumption question in three old sections, untimed, saying the negation out loud. Week two is diagramming every conditional and writing the contrapositive, plus one timed section a day to keep the feel. The weekly proctored test continues throughout, with blind review and the tally.

Most students see the tally shift within two weeks: the targeted categories shrink and something else becomes the biggest bin. That is the plateau moving. You then repeat the process on the new biggest bin. Nine questions, two bins at a time, is a reasonable 8- to 12-week project for a student who is honest in review. Not a promise, a target. The 16-week schedule lays out the cadence in full.

What to do this week

1. Take one official PrepTest, current format, fully proctored. Four 35-minute sections, one break, no pausing.
2. Blind review before checking answers. Rework every flagged question untimed and record a second answer.
3. Sort every miss into the five bins plus “can’t name it.” Write the tally on one page.
4. Pick the two biggest bins and drill only those, untimed, for the next six days, using the checks in this guide (negation test, subject match, contrapositive check, circle the quantifier, “what happens to the conclusion”).
5. If “can’t name it” holds four or more misses, send us the PrepTest and the tally for a diagnostic debrief instead of drilling blind.