Difficult Moves is a PRO feature, which shows the moves and variations you find most problematic during review.

A difficult move shown on the dashboard is defined as having 3 or more mistakes and a review score below level 4 (+70 points).
​

For all difficult moves regardless of the number of mistakes, you can access the list via Tools > Difficult Moves.

The page displays a board and a list of moves/positions, starting with the lowest accuracy.
​

Clicking on any of these entries will display the position on the board; the correct and incorrect moves played during review, and how many times the moves were played.

Note that you can also filter the list of moves/positions by course, chapter, or variation name (using the search box).

Here are the two most common ways to use the information gleaned from Difficult Moves:

1. Overstudy the most problematic moves. Revisiting, reviewing, and re-evaluating how you understand the move before it's up can improve your retention. So when game time comes, you're ready to play accurate chess.

2. Identify the nature of your mistakes, so you can try to fix them. Sometimes, when training tactics, we commit mistakes. The cause of this is most likely overconfidence and superficial calculation.

If you're playing willy-nilly in training, then you're also prone to commit the same errors in competitive games. So you must fix those game-ruining tendencies.

You may also access the Difficult Moves list for a course via the dashboard. In the screenshot, there are 3 difficult moves in Tactics Time 1. Clicking on the highlighted button confirms this (please see the below image).
​

The number (just beside "Click Here For Problem Solution") indicates the number of times an incorrect move was made. The color-coding of the number also changes, depending on the last time you reviewed the move:

To learn how to clear your Difficult Moves list, please check this guide: