LSAT PrepTests by Number, with Relative Difficulty Assessments

The chart below shows how many questions a test-taker would need to get right in order to achieve a 150, a 160, or a 170 on each published PrepTest.

Every right answer on a test is worth one "raw point." LSAC turns those raw points into scaled points—the overall 120–180 score—by comparing everyone's performance on a particular test.

Perhaps counter-intuitively, a more difficult scaling indicates that the test itself was easier - it means that more people got more questions right, so that for any given scaled score, a tester would have had to earn more raw points than they would have on a test where more people missed more questions.  

For example, on PrepTest 118, a tester would've needed to get only 67 questions right to earn a 170. But on PrepTest 121, a tester would've needed to get SIX more questions right to earn the same score. That means 121 was an easier test: more people got more of the questions right overall, so people were not rewarded as much for getting questions right. 

So, here, cooler colors (BLUES) mean stingier scaling, on EASIER tests. 

Warmer colors (ORANGES) mean more-generous scaled scores on HARDER tests.  

Takeaway: over time, it's taking slightly FEWER points to earn a 150 or a 160, but it's taking slightly MORE points to earn a 170.