alt.hn

5/14/2026 at 3:19:05 AM

Arena AI Model ELO History

https://mayerwin.github.io/AI-Arena-History/

by mayerwin

5/14/2026 at 8:41:30 AM

Neat. Would you add the option to normalize the elo over time (e.g update the model used as an anchor for the elo computation) so the diff between labs is more visible?

by whiplash451

5/14/2026 at 5:06:00 AM

> the slow performance decays

the decays are just more capable other models entering the population, making all prior models lose more frequently

by underyx

5/14/2026 at 8:23:33 AM

No, that is not how ELO scores work.

by TekMol

5/14/2026 at 8:37:34 AM

It depends what you use as an anchor. If the anchor is a fixed model, you’re right. If the anchor is updated to a better model over time, then the elo of historical models degrades, right?

by whiplash451

5/14/2026 at 5:46:27 AM

For what it's worth, I work at OpenAI and I can guarantee you that we don't switch to heavily quantized models or otherwise nerf them when we're under high load. It's true that the product experience can change over time - we're frequently tweaking ChatGPT & Codex with the intention of making them better - but we don't pull any nefarious time-of-day shenanigans or similar. You should get what you pay for.

by tedsanders

5/14/2026 at 5:53:36 AM

> we don't switch to heavily quantized models

That sounded like a press bulletin, so just to let you clarify yourself: Does that mean you may switch to lightly quantized models?

by selcuka

5/14/2026 at 6:03:44 AM

There's almost 0% chance that OpenAI doesn't quantize the model right off the bat.

I am willing to bet large amounts of money that OpenAI would never release a model served as fully BF16 in the year of our lord 2026. That would be insane operationally. They're almost certainly doing QAT to FP4 for FFN, and a similar or slightly larger quant for attention tensors.

by jychang

5/14/2026 at 6:07:58 AM

It's ok if they never release a BF16 model, but it's less ok if they release it, win the benchmarks, then quantise it after a few weeks.

by selcuka

5/14/2026 at 8:30:12 AM

its very interesting to see that this only happens to American companies. What gives?

by _kidlike

5/14/2026 at 5:58:32 AM

Thank you for your answer. I have a similar question as OP, but in regards of the GPT models in MS copilot. My experience is that the response quality is much better when calling the API directly or through the webUI.

I know this might be a question that's impossible for you to answer, but if you can shed any light to this matter, I'd be grateful as I am doing an analysis over what AI solutions that can be suitable for my organisation.

by Ciph

5/14/2026 at 8:08:28 AM

As phrased the only answer is the question; "as opposed to what?"

by sans_souse

5/14/2026 at 8:02:32 AM

webUIs have giant system prompts built in

APIs have much smaller ones

by aiscoming

5/14/2026 at 8:32:35 AM

Very neat! It would be great to extend it to non-flagship models as well.

by fph

5/14/2026 at 8:24:15 AM

Seems like Chinese labs are the only ones that are trustworthy (at least when it gets to this specific issue). This feels so ironic haha

by ponyous

5/14/2026 at 6:50:12 AM

The interesting thing I find is how Anthropic has been more consistently improving over time in the last few years, that allows it to catchup and surpass OpenAI and Google. The latter two have pretty much plateau over the last year or so. GPT 5.5 is somehow not moving the needle at all.

I hope to see the other labs can bring back competition soon!

by cherioo

5/14/2026 at 7:10:28 AM

Gpt 5.5 is quite a big leap, it's a lot better than opus 4.7 for agentic coding

by XCSme

5/14/2026 at 8:30:07 AM

Better in what ways? I'm just curious about your experience.

by mettamage

5/14/2026 at 8:37:10 AM

Consistency, not making mistakes.

by XCSme

5/14/2026 at 8:40:34 AM

Ahh... that is indeed an issue I have with Claude. I'll check it out!

by mettamage

5/14/2026 at 7:19:46 AM

Arena only allows very small context sizes, so it's a noisy benchmark for what we care about IRL.

by energy123

5/14/2026 at 7:23:10 AM

Although Arena is adversarial and resistant to goodharting, it's not immune. Models that train on Arena converge on helpfulness, not necessarily truthiness

by kimjune01

5/14/2026 at 7:19:10 AM

This is great, but personally, I really wish we had an Elo leaderboard specifically for the quality of coding agents.

Honestly, in my opinion, GPT-5.5 Codex doesn't just crush Claude Code 4.7 opus —it's writing code at a level so advanced that I sometimes struggle to even fully comprehend it. Even when navigating fairly massive codebases spanning four different languages and regions (US, China, Korea, and Japan), Codex's performance is simply overwhelming.

How would we even go about properly measuring and benchmarking the Elo for autonomous agents like this?

by jdw64

5/14/2026 at 7:21:57 AM

Isn't code that you fail to understand literally a sign that its worse?

by vachanmn123

5/14/2026 at 7:23:01 AM

It was often much faster, and when I revisited the code later, there were cases where I realized it had moved the implementation toward a better abstraction.

by jdw64

5/14/2026 at 7:33:42 AM

I should also add that I am not claiming to be a particularly great programmer. I have never worked at FAANG, and I haven't had much exposure to the kind of massive codebases those engineers deal with every day.

Most of the code I've worked with comes from Korean and Chinese startups, industrial contractors, or older corporate research-lab environments. So I know my frame of reference is limited.

When I write code, I usually rely on fairly conservative patterns: Result-style error handling instead of throwing exceptions through business logic, aggressive use of guard clauses, small policy/strategy objects, and adapters at I/O boundaries. I also prefer placing a normalization layer before analysis and building pure transformation pipelines wherever possible.

So when Codex produced a design that decoupled the messy input adapter from the stable normalized data, and then separated that from the analyzer, it wasn't just 'fancier code.' It aligned perfectly with the architectural direction I already value, but it pushed the boundaries of that design further than I would have initially done myself.

This is exactly why I hesitate to dismiss code as 'bad' just because I don't immediately understand it. Sometimes, it really is just bad code. But sometimes, the abstraction is simply a bit ahead of my current local mental model, and I only grasp its true value after a second or third requirement is introduced.

To be completely honest, using AI has caused a significant drop in my programming confidence. Since AI is ultimately trained on codebases written by top-tier programmers, its output essentially represents the average of those top developers—or perhaps slightly below their absolute peak.

I often find myself realizing that the code I write by hand simply cannot beat it

by jdw64

5/14/2026 at 5:38:15 AM

The Elo rating system measures relative performance to the other models. As the other models improve or rather newer better models enter the list, the Elo score of a given existing model will tend to decrease even though there might be no changes whatsoever to the model or its system prompt.

You can't use Elo scores to measure decay of a models performance in absolute terms. For that you need a fixed harness running over a fixed set of tests.

by eis

5/14/2026 at 8:10:57 AM

The relative and auto-scaling nature of Elo ranking feels like an advantage here.

Relative ranking systems extract more information per tournament. You will get something approximating the actual latent skill level with enough of them.

by bob1029

5/14/2026 at 8:21:27 AM

Advantage for what exactly though? I'm not saying Elo Ranking doesn't give any information. It just doesn't give the information that the OP's project claims to be able to give: that models get nerfed over time. You could extract this kind of information from the raw results of each evaluation round between two models, ignoring any new model entries and compare these over time but not from the resulting Elo scores with an ever changing list of models.

New models are on average better than older models, the average skill of the population of models increases over time and so you are mathematically guaranteed that any existing model will over time degrade in Elo score even though it didn't change itself in any way.

Elo is good at establishing an overall ranking order across models but that's not what this is about.

by eis

5/14/2026 at 5:43:52 AM

FYI, Elo isn't an acronym - it's a person's name. No need to capitalize it as ELO.

by tedsanders

5/14/2026 at 7:10:12 AM

Unless you've just missed your last train to London.

by andrewshadura

5/14/2026 at 5:45:45 AM

You’re right: https://en.wikipedia.org/wiki/Elo_rating_system

by SilverElfin

5/14/2026 at 6:38:18 AM

> ELO ratings

Thank you, I just looked at the chart and said to myself: ELO? YOLO!

That Elo ranking is also called chess ranking

by gitowiec

5/14/2026 at 7:12:22 AM

Élő. Meaning alive (él = it lives, -ő = adjective)

by andrewshadura

5/14/2026 at 6:52:14 AM

It seems to be a USA only thing, Chinese models and Mistral don't show any downward trend.

by Thomashuet

5/14/2026 at 7:39:12 AM

Wouldn't it be really weird if a open-weight model dropped in performance? Because then, it would rather be the Elo ranking

by patall

5/14/2026 at 6:04:23 AM

Is this slop? It has wildly aggressive language that agrees with a subset of pop sentiment, re: models being “nerfed”. It promises to reveal this nerfing. Then, it goes on to…provide an innocuous mapping of LM Arena scores that always go up?

by refulgentis