Kevin

• Immediately exit in moveloop pruning if triggered (7 Elo)
• Give more history bonus and cap it (8 Elo)
• Allow more LMR (18 Elo)
• Fix an illegal move bug This will probably be my last update before the end of SoM. It was fun meeting yall!

• Don't allow NMP in singular search (10 Elo)
• Compile with LTO (15 Elo)
• Add node time management (24 Elo)
• Lower history values each search (8 Elo)
• Fix node counting (5 Elo)
• Do not store best move on TT fail-low (4 Elo)
• Fix checkmate (1 Elo)
• Disallow IIR at expected all-nodes (12 Elo)
• Raise singular extension beta (8 Elo)
• Disallow corrhist update on mate scores (5 Elo)
• Relax SE bounds (5 Elo)

• Adjust soft bound based on search complexity (9 Elo)
• Only do NMP at sufficient depth (6 Elo)
• Prefetch TT values before recursing (7 Elo)
• Reduce killer moves less (16 Elo)
• Increase overall LMR (7 Elo STC, 9 Elo LTC)
• QS Prior Extensions (5 Elo)
• NMP Improving (4 Elo)

I actually might just be the goat, this is the largest green wave we've seen in a while
- Use optimized move picking in qsearch instead of std::stable_sort (which is slow) (4.5 Elo)
- Optimize capture generation for qsearch (6 Elo)
- Optimize NNUE inference with Finny-like tables (15 Elo)
- Only store upper 32 bits of hash (5.7 Elo)
- Fail-firm beta adjustment when failing high (16.6 Elo)
- Simplify Finny NNUE inference (1 Elo)
- Modify time allocation (8.3 Elo)

• Disallow LMR at low depths (7 Elo)
• Disallow LMR for early moves (5 Elo)

• Allow razoring up to depth 8 (+2 Elo)
• Do more NMP if score is far above beta; depth cap RFP (+5 Elo)
• Add nonpawn corrhist (+8 Elo)

• Re-train NNUE again
• Allow adjustments to NMP margin based on current depth (+10 Elo)

• Generate another 600M positions for the neural network
• Cutnode reductions (4.8 +/- 3.5 Elo)
• Dynamic PVS SEE margin (5.2 +/- 3.8 Elo)
• PrevMove CorrHist (6.7 +/- 4.4 Elo)
• TT-corrected QS evals (8.9 +/- 5.2 Elo)

• Create a cool little visualization thing for the NN weights

• Do some retrains of the main evaluation NNUE
• Continue with self-gen, gain another +20 Elo from WDL updates (0.15 -> 0.40)

• Continue tweaking the new method (normalization helped it gain @ LTC but hindered its performance @ STC), now only gaining +3 Elo
• Not sure if I want to merge this into PZ ... but we'll see

Try a completely new pruning method (cut net) that gained +15 Elo (WTF!!!!!)
Might PR this idea into Stockfish and see if it can also gain from this

• Test the new neural network against v3.0 (+16.0 @ STC, -4.7 @ LTC)
• Test the new neural network against generation 12 of the self-trained neural network (+16.5 @ STC, +30.7 @ LTC)

• Completely overhaul the PVSearch mechanism in PZChessBot
• Fix PV handling (for the most part; still some weird edge cases)
• Modify training schedule and prepare to train next generation of NNUE w/ 2.6 billion positions (78GB of data)

Continuing on with general QoL fixes in PZChessBot since the search is pretty much complete :)
- Add MultiPV support
- Test 3-PV vs 1-PV @ fixed depth=10 (+57 Elo)

• Try adding cutnode reductions (to no avail, again)
• Test disallowing NMP in PV nodes
• I think my nodetype handling is kinda cooked

• Add a web-playable version, compile with WASM

• Continue self-generated NNUE
• Change to using 5 buckets and also shuffle data (+30 Elo)

• Fix the TT issue that has been cooked for a while (+11 Elo) Basically, I was storing everything into the TTable as an UPPER_BOUND (which is obviously wrong), but fixing this bug would always lose Elo. The problem was that I was doing TT cutoffs in PV nodes, which is expressly disallowed; but only recently discovered this problem...

• Test out a bunch of tweaks, including:
• Lowering RFP threshold to 100 (+2.8 Elo)
• Center control evaluation term (+10.2 Elo)
• King safety evaluation term (+11.3 Elo) Around 2500 Elo now for the HCE version of the engine!

• Also use PeSTO values for material, and switch the tapering system to use PeSTO's system (+148 Elo)

• Tweak the eval function to prioritize rooks on 7th (+15 Elo)
• Use PeSTO PSQTs (+120 Elo)

• Add bishop pair bonus (+9 Elo)
• Taper the PSQTs for endgames for pawns and kings (+79 Elo)
• Test adding mobility bonus but my code is too slow for it to gain Elo... maybe in the future

• Begin working on the hand-crafted evaluation part of the engine
• Restarting from scratch (with just material counting), added PSQT (+270 Elo)

• Touch up the data generation script to skip heavily biased starting positions
• Generate another 500M chess positions for training the network!
• Also did a small change where instead of only deepening the search for the hash move, singular extensions actually raised the depth of the entire node (+3 Elo)

• Use an LLM to generate voicelines
• Optimize voiceline playback by precomputing them

• Add basic death detection (still misfires sometimes)
• Tune up kill and death detection by only triggering when it is active for 3 or more frames

• Add basic kill detection by using a Hough circle transform
• Use a basic TTS library (a better one will be added later)
• Begin working on death detection but it's very cooked

Added pretty console output! It looks really great IMO

• Add QSearch Futility Pruning (+7 Elo)
• Reduce less on PV nodes (+5 Elo)
• Reduce more when the TT Move is a capture (+6 Elo)
• Fix killer move logic (+18 Elo)
• Train a new horizontally mirrored network (+28 Elo)
• Add PVS SEE pruning (+24 Elo)

• Rewrite move ordering scheme (+5 Elo)
• Implement LMP (+8 Elo)
• Implement singular extensions (+5 Elo)
• Implement negative extensions (+13 Elo)
• Implement history pruning (+21 Elo)
• Do more RFP when improving (+18 Elo)

Write a few more blogs on other chess engine content and philosophy content

• Run an SPSA (+5 Elo)
• Do not reset Transposition Table on position command (+65 Elo!!!!!)

• Only do NMP when eval is above beta (+12 Elo)
• Only call TT once per node (+12 Elo)
• Add razoring (+31 Elo)

• Used TT eval instead of static eval when available (+10 ELO)
• Use lazy sorting (+2 ELO)

• Test various tweaks, including:
• always replace scheme for TTable
• lazy sorting in main
• doing NWS first in PVS, even after score > alpha condition is met
• disallowing RFP in mating positions (for more accurate mating scores)

none of these passed :(

Deploy the site onto Cloudflare pages (for now)

Also bought a proper domain, currently waiting for DNS records to propagate before the page is moved onto the domain

Add a few more pages, most notably an about me page

https://int0x80-ca.pages.dev/

• Created the actual site interface
• Created a minimal design for blogs
• I like how the site looks!

Write more fun extra blogs!

Continuing rewrite:
- Implemented check extensions (50 ELO)
- Implemented proper time management (30 ELO)

Testing:
- Futility Pruning
- QSearch Futility Pruning
- Capture History Heuristic

Write blogs on:
- Aspiration windows
- PV Search
- RFP & NMP
- SEE
- FP
- Time management
- Extensions

• Continuing rewrite
• Implemented quiescence, transposition tables, aspiration windows, PVSearch, RFP, NMP, SEE, and FP
• We're already back to 3200 ELO!

To answer @nosrep, I'm rewriting the search because I wrote the bulk of the foundation for the search back when I didn't really know much about chess engines. As a result, my search code is, honestly, extremely messy and difficult to deal with. So, I'm trying to clean it up (along with fixing a few bugs and adding some small microoptimizations)! Also, when I wrote the base search, I didn't know how to properly test code either, so I just made changes and hoped they made the engine stronger. Now, by testing all my changes, I can be sure that my engine is actually stronger, and also I can document my progress and write blog posts on it!

• Begin working on rewrite of search
• Implemented a/b pruning, basic move ordering (MVV-LVA, Killer Moves, HH)
• Also documenting progress on int0x80.ca (other project)

• Wrote first 6 posts on chess engine development

• Add static exchange evaluation in quiescence search (~20 ELO) ~3300 ELO now

• Messed around with trying to add Horizontal Mirroring to optimize my NNUE inference but didn't work (will be revisited soon)
• Flesh out data generation workload, tool is fully working now (~3.5kpos/s)
• Test adding Capture History to QSearch
• Test using a model trained on 0.05WDL instead of 0.15WDL

Start working on self-gen data for self-training network
Tried a variety of small improvements that didn't work :(

• Finally got CorrHist working (+7 ELO)
• Still waiting on other tests that will take eons

• Figured out why my pawn corrhist wasn't working
• Waiting on SPRT results (again)
• Broke the bank to rent a 48CPU Google server to speed up tests
• Please help my sanity

• Various small speed optimizations (~4 ELO)
• Try adding Pawn CorrHist (but it's failing miserably) We're like 3250 ELO right now!

• Completely overhaul the NNUE evaluation system
• Change network to use king input buckets (~54 ELO) Insane change for an insane amount of ELO

• Add extended futility pruning along with another SPSA tune (~11 ELO)
• Testing adding internal iterative deepening, seems to not be doing too well (-0.95 +/- 4.3 ELO)
• Testing increasing the NMP R-value from 4 to 5, awaiting results right now

• Change history heuristic to use history gravity formula (~16 ELO)
• Add capture history heuristic to make MVV-LVA -> MVV+CaptHist (~14 ELO)
• Allow RFP to be performed at all depths (~5 ELO) Engine is now around 3160 ELO, putting it around 140th in global standings

• Added futility pruning (~20 ELO)
• Vectorize nnue_eval() (~7 ELO)
• Run a full SPSA tune of values and use the tuned values (~20 ELO) Didn't have time to run a progtest but it's looking good!

• Improved aspiration window logic to gradually widen instead of defaulting to a full-window search (~20 ELO)
• Improved time management to include a soft bound (~20 ELO) Engine should be around 3120-ish ELO now, putting it around 160th in global rankings (further testing needed)

• Fixed many bugs
• Fixed mate handling
• Around a 500 ELO gain over the previous version

Finalized some stuff for the v2.0 release! Not too sure if I will continue work (since most of it will be with NNUE stuff and that's really :( and also because engine dev is getting really dry)

Spent the first few hours just working on basic RSA implementation. Currently, it's very scuffed and isn't secure at all, but it works! I can communicate with encrypted messages given a public key, then decrypt it with my private key.