I'm a big fan of the Problem of the Week posts and have learnt so much from them. To test myself I created a viewer where I could replay each position until I get them right. I've called it BG Test and I have put it online for everyone to use. You can find it here. Please go ahead and try it out. It's not finished yet but I would appreciate any feedback, good or bad. The idea is that you can keep testing yourself on positions until you stop making errors. Also, you can easily go to the lessons that you need to review.

Hope you enjoy.

I'd put the diagrams to 150% size so the user doesn't have to do it himself.

You need to change 'Equity' to answer or something better than equity.

You should also have a back button.

Thank you DGP. Great suggestions and I have added a back button and changed Equity to Answer on the button. I was never quite comfortable with the Equity label. I have also added the question number so you can see where you are when going backwards and forwards.

The display size is a problem because of the different size screens that people use from phones to desktop monitors. It might just have to stay at the current default size for now.

Great! Also, from the main page I would change it from 'Load' to 'Start' or something similar.

Why is it that the URL doesn't change in the address bar? I prefer that it did. That way people like me can also navigate changing it.

Great feedback. I changed the label to Start as you suggested and moved it to the bottom of the screen. I added in some keyboard shortcuts. Just type the first letter of the button label - s for start etc.

The URL doesn't change because it is all written in javascript (it's what I know best). You will see that the position number is after the Question No. I've made this clearer.

You can add the position number to the url by adding to the end ?i=12
Or you can add a list of numbers with ?i=12,225,188 This makes it easier to replay your mistakes or share with others.

Pressing the Mark makes a link for you as you go along. You can see it working at the bottom of the screen.

Shortcut keys are not working in Chrome. Will work on this later.