Practicing an opening


How to Learn an Opening in 2023: Part 2

Use practice games to improve your repertoire one move at a time, and spaced repetition to ensure you never forget your preparation

This is part two of my guide to preparing an opening in 2023. In part 1 you learned the basics of the opening and created a file to document your knowledge.

Practice your opening

Now that you have a grounding in the key variations and ideas of your opening, which you’ve captured in an opening file, you’re ready to start practicing the opening in real games. Notice that you get to this step very quickly, having invested only a few hours in learning the opening.

I like to get my hands dirty with real games as quickly as possible for several reasons. I find that if I learn lines after encountering them in a game, my knowledge is much stickier and more relevant, because I’m learning them as solutions to in-game problems I’ve already grappled with, rather than random sequences of moves that may or may not be valuable.

If it turns out I really don’t like the positions I get from an opening I can abandon it without wasting too much time. But this is rarely necessary, and I’d advise you not to abandon an opening too quickly. It takes a while to get up to speed and you don’t want to give up before giving it a fair chance. In particular, complex main lines take some time to get a feel for, but once you do the rewards are big. When I learn an opening, there’s often a point between a few weeks and a few months where I start winning many games easily because my opponents make mistakes I’ve seen before or I get to use typical plans that I’ve already seen. If you constantly change openings too quickly you’ll never get to this point.

But let’s talk about the mechanics of practicing an opening. There are two approaches, but one is much better than the other. The better approach is to set up a match with a friend or training partner. The advantage of this approach is that you can specify that you’ll play the opening you want to practice in every game. For example, if you want to practice the Sicilian, find someone around your level who plays 1. e4 and set up a time to play a few games. This avoids one of the big frustrations with learning a new opening, where you’re excited to try it out, but no one plays into the line. For example, I calculated that you would only get the Nimzo Indian in about 5% of your total online games. If you only get a line in 1/20 games, you’re likely to have forgotten your preparation before you get a chance to practice it.

Another advantage of setting up a focused training session is you can play a slower time control, which can sometimes be hard to find opponents for online. I find that 10+5 rapid is a great time control for practicing openings, but you can use any time control you want. Finally, one more advantage is that you can analyze the games with your opponent afterwards. A back-and-forth discussion will create highly memorable knowledge of the opening.

If you’ve followed the plan so far, you’re already better prepared than most players, with only a few hours invested. But more importantly, you now have the framework in place to continuously improve your knowledge of the opening.

Updating your file

After your training games – and after any games you play in the opening in the future – I recommend updating your file using the “one move rule.” According to this rule, you update the file to the first move you would have played differently.

Using the one move rule ensures that your opening study workload stays manageable and relevant. But if you play consistently, you can improve your opening repertoire very quickly using this method. I like to set up a focused training session right away to get a blast of practice in the opening I’m focused on, but with that squared away, you can certainly keep playing online blitz or rapid games against randomly paired opponents. You might not get the specific opening you’re learning all that often, but ultimately you want to work towards having files for all your openings, so no matter what your opponent plays you’ll have something to update.

How do you choose which moves to add to your file? If you’re working from a source like a book or course, start by checking if the move your opponent played is covered in your source. If it is, and you’re happy with the recommendation, you can simply add it to your file. If it’s not covered you need to figure something out for yourself. In this case the engine and database are your best resources. If the engine has a clear top move, that’s usually the move you’ll want to play: it’s simply the best move. If many moves are close, you can choose based on other factors, such as the move that’s easiest to remember, most consistent with the rest of your repertoire, or scores best in practice. Regardless, never add a move you don’t understand to your file. If the engine line doesn’t make sense to you, explore it until you understand what’s going on. And make sure to capture your understanding with written explanations in your file.

For example, in this position I played Nc6, but later had problems developing my light-squared bishop. After reviewing the game with the engine I saw that a better setup is to play b6, develop the bishop to b7, and often put the knight on d7. According to the one move rule, I add the move b6 in this position as well as a note about the position.

Use spaced repetition

Spaced repetition is a technique for remembering information by reviewing it at intervals of increasing length. I have a whole post on the theory behind this technique, but for now suffice it to say that it’s very effective for building durable memory with a minimal time investment. I would 100% recommend using spaced repetition as part of your opening preparation system. For me, incorporating spaced repetition was the difference between forgetting my lines all the time and almost never forgetting them.

When it comes to applying spaced repetition to chess, you have several choices. The most well-known is Chessable. In fact, using spaced repetition for chess is the core idea the whole platform is based on. If you chose a Chessable course as your main resource for learning your opening, you’re already all set up to do spaced repetition training on Chessable. When you go to the site you can just click “Review All Courses” to review the lines that are due. Amazingly to me, many people who purchase courses on Chessable don’t actually use the review feature. This is strange because it’s the main advantage Chessable has over an old-fashioned chess book, and it’s extremely valuable. I think there’s a misconception that “focusing on the ideas” in openings means you don’t have to know the moves. In fact, with some coaches urging players not to study the opening, there seems to be a sense of shame around studying the opening in general, and memorizing variations specifically. So let me just be clear: you should study the opening, and you should memorize some variations. The problem comes when you memorize too many long, irrelevant variations and it eats up your study time. But the solution to this isn’t not remembering your lines, it’s including fewer, shorter lines to begin with. But if a line is part of your preparation, you should definitely remember it!

While Chessable has a lot of great courses (like mine!), it’s not as good for creating your own material. It is possible to make your own custom course, but unfortunately, the process for creating and updating a custom course is pretty clunky. For that reason, I’ve been using a different site, Chessbook, for practicing my own files. Like Chessable, Chessbook manages your spaced repetition schedule for you behind the scenes. Unlike Chessable, it doesn’t have any premade repertoires that you can purchase, but it makes the process of creating your own repertoire much easier. You can add your own lines either by importing a pgn or by entering moves on the board. If you decide to use Chessbook, you can get started very easily by copy-pasting the pgn of your opening file.

When I update my repertoire using the one move rule, first I decide what moves to add and write any relevant notes in my Lichess study. Then, if I feel the line is important to remember, I manually enter the moves into Chessbook. At first I wished Chessbook would automatically sync with my Lichess study, but after using the process a bit more, I think this additional step is actually a benefit. Manually entering the moves gives me an opportunity to practice the line and make sure I actually understand it. I also think it makes sense to have a somewhat more detailed file, but not all of it needs to become part of your spaced repetition schedule. Remember, when you add something into the spaced repetition system, you’re committing to memorizing it. I make a judgment call: if the line is popular, challenging, or important, I’ll add it to spaced repetition; if it’s rare and I can figure out how to respond over the board, I’ll leave it out.

Conveniently, both Chessable and Chessbook have mobile apps. Reviewing your lines is a great thing to do when you have a few minutes, but not enough time or focus for more intense training like calculation exercises. I was only half-joking when I tweeted that if you have too many reviews to complete on the toilet, you’re learning too many new lines. You should really be able to finish all your reviews in a few minutes per day. If you can’t, don’t add any new lines until you’re able to clear them out. And if you find yourself in a spot where you have many thousands of review lines piled up, I’d suggest resetting your courses and starting over with the knowledge that you need to go much slower.

Currently I use both Chessable and Chessbook: Chessable for openings where I’m following someone else’s course, and Chessbook for openings I’m preparing on my own. There are also other tools that let you use spaced repetition for openings, like Chesstempo, but I haven’t used them so can’t comment directly. One way or another, I would definitely recommend that you use spaced repetition to make sure to remember your opening lines.


You now have a process in place to continuously improve your opening repertoire. The beauty of this system is that once you’ve invested a few hours up front to set it up, it takes very little time to maintain. You just update your file when you play a game in the opening and spend a few minutes per day reviewing lines with spaced repetition. As long as you stick with the same openings, you don’t have to do any more than this. This is how you build a better opening repertoire while freeing up more time to work on other parts of chess. Give this system a shot and let me know how it works for you.

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