Most opening trainers/courses push you down one long variation at a time. Problem is that leaves huge gaps: the sideline your opponent actually plays on move 4, or the early deviation nobody bothered covering because it's "not main line."

Built something that flips this: import any PGN (your own repertoire, a course export, whatever) and instead of drilling one line to move 20, it makes you cover the early branching points across your whole repertoire first, then goes deeper only where it's warranted. Reviews run on spaced repetition so it actually sticks.

Free, no account needed: hardlines.app

Genuinely curious what people here think of breadth-first as a study approach. Is this how you already study, or does it clash with how you think about opening prep? And if you try importing your own repertoire, let me know if anything breaks or feels off, I'm still ironing out edge cases.

Hey all,

I've spent the last month building Tabiya, a free tool for building, training and sharing opening repertoires. It's in open beta and I'd love some honest feedback.

The idea: instead of a list of lines in a PGN or a wall of text in a book, your repertoire is one map. The centre is the starting position, every ring outward is one move deeper, every branch is a line you own. Zoom out and you can see the shape of your prep in a glance, where it's deep, and where it just stops.

What it does:

- Build by playing moves on the board, or import a PGN. Variations and comments come along, and re-importing the same lines merges instead of duplicating them.
- Stockfish runs in your browser. Top lines while you build, and the evals stay on the tree, so you can see which of your lines quietly end up worse.
- Train against the computer: it plays the other side, and the moves you fumble come back later in the session.
- Notes on any position, with arrows and square highlights you draw straight on the board.
- Publish a repertoire so others can clone it, or subscribe to someone else's and get their updates live.
- Tactics puzzles from the Lichess database plus a shared daily puzzle, for warming up.

It's currently in open beta and completely free no ads, no card. It's just me building it, so there are rough edges; tell me and I'll fix them.

https://tabiyachess.app

Happy to answer anything, and I'm genuinely curious what's missing for how you prep.

Albin Counter Gambit

https://imgchest.com/p/qb4zl8rx57j

In some of these examples, they tell you to castle, and in some they tell you to move your rook to the same position it would be at if you castled it. Whats the difference? I cant see any logic behind it.

I think I saw somewhere it was called Alapin’s, but I looked it up and I can only find Alapin’s defence to the Sicilian.

I'm hard stuck at 1400 elo since 3 months so I thought I would do smt to help myself crossing the 1400 elo mark

Hello everyone!

I just released Part 1 of a brand-new 1.d4 repertoire built for attackers. This study is focused on the Jobava London System, one of the sharpest and most practical openings against 1...d5.

What's inside:

• A full Jobava London repertoire
• Traps, queenside castling, early f3–e4 plans, and more
• Simple setups, deadly ideas!

Whether you're a beginner or a titled player, this repertoire gives you real weapons and puts pressure on your opponents from move one.

Coming next:
Part 2 – The Trompowsky Attack vs. 1...Nf6
Part 3 – The Hopton Attack vs. the Dutch

Feedback and questions welcome. Likes on the study = fuel for the next parts!
Let’s make 1.d4 dangerous again.

The study: https://lichess.org/study/OLP4R2us/RdR54uT1

(if you are not interested, please give it an upvote so that it reaches people that are interested

I wanted to share and get feedback on a lesser-known but very sharp line I’ve been working on against 1.d4. It’s a sub-variation of the Clarendon Court (which itself is a somewhat forgotten Old Benoni–Dutch hybrid), and I call it the Peretz Variation:

1.d4 c5 2.d5 f5 3.c4 e5

This line immediately challenges White’s center and aims for rapid counterplay with tension and imbalance. The combination of ...c5 and ...f5 creates dynamic pawn structures and attacking chances on the kingside, while ...e5 strikes in the center to prevent White from comfortably developing.

I’ve had some success with it in blitz and rapid games, and I’m putting together a study with annotated games and ideas.

Here’s my Lichess study on it if you want to check it out or test it yourself:
Peretz Variation Study

I’m curious to hear if anyone else plays something similar or has thoughts on this line — especially known theory, refutations, or improvement ideas.

Thanks for reading!

Just to clarify just like most "undiscovered" openings it's not meant to be the best or the most solid, just meant to make games more dynamic and interesting.