Nicholas Pert has excellent credentials as both an author, with his excellent DVD on the French Defense, to his position as National Head Coach for the English Chess Federation, suggesting his experience and success as someone helping players reach their potential is a matter of record.

In his introduction he explains that the work is aimed at players in the 1600 Elo to 1900 Elo range, and is based on a research he did to identify trends in mistakes made by players of that caliber. Naturally a great many deal with tactical errors, and he acknowledges this, but they are not the only ones by any means, and common positional or endgame mistakes, that even these players should not need to commit, will be covered. The themes are explained with multiple videos, and then tested via quizzes.

The contents is crystal clear as is the structure of the DVD:

01: Introduction - Mitra,R - Sit,V 
Chapter 1: Not admitting a mistake  
02: Video 1 - Kuznetsov,F - Petruchuk,M  
03: Video 2 - Shirshov,N - Nielsen,A 
04: Test - Batchelor,G - Sucikova,S 
Chapter 2: Failed Sacrifices 
05: Video 1 - Galiana Fernandez,A - Antonian,G 
06: Video 2 - Ruiz Escobar,I - Navarro Gonzalez,J 
07: Video 3 - Sarabia Utrilla,J - Pardo Vaquero,I 
08: Test - Beukema,J - Mclaren,C 
Chapter 3: Be aware of opponents threats 
Chapter 4: Standard Endgames  
Chapter 5: Too materialistic 
Chapter 6: Miscalculating forced lines    
Chapter 7: Exchanging Bishops for Knights  
Chapter 8: Pawn Structure 
Chapter 9: Improving worst piece 
Chapter 10: King safety 
Chapter 11: Overestimating opponents plan

I removed the lists of videos and tests in the other chapters as it was quite long, but suffice it to say there are 57 videos in all, divided between lessons and interactive quiz videos. If that sounds like a lot, it is, but do not worry, they are all extremely palatable. The overall time of this work is listed at bit over four hours, not fourteen.

The student will find an impressive list with 57 videos covering lessons and tests

Although I am no longer in that rating range, I can certainly sympathize with pretty much every single theme. In fact, I don’t think any of these mistakes are above masters even, they just commit them less often and at a higher standard. Miscalculating forced lines? Check. Not admitting a mistake? Check. Overestimating opponent’s plan? Check! Nevertheless, that only shows that players need to start pounding these lessons early on, in order to maximize their chances of minimizing them.

GM Nicholas Pert explains his goal and plan to help players avoid the most common mistakes 

The chapters are all well-presented, with short videos presenting a game between players in the 1600-1900 range. GM Pert sometimes shows an entire game, and sometimes starts at a key moment. He explains the error made, speculates on the reason they were made, trying to help the viewer analyze his own thoughts and see if he sometimes thinks the same way. He provides the correct way to proceed and gives guidelines to avoid making the same mistake. All the advice is well-founded and eminently practical. If someone sacrificed material against you, be sure you cannot take before rejecting it simply because it looks scary.

In this video, White has planted an annoying knight on d8, attacking the rook. What should you do? GM Pert explains why taking the knight with the bishop wouold be a mistake.

After the lectures there are video tests to help see how well the lesson was understood, and again all are taken from amateur play, reinforcing how common these mistake are. And finally there is a small database of commented games that focus on the lessons at hand.

Here is an example based on the lesson “Exchanging Bishops for Knights”:

I found the author's lessons well-chosen and more importantly: clear in both the material, what went wrong, and how to avoid the issues illustrated. If you feel your growth is not where you want it, and are tired of making the same mistakes, this DVD is for you.

Typical Mistakes by 1600-1900 players can be bought in the ChessBase Shop