The 80/20 Problem of
LLM Tuning
How tuning shapes performance
Made by Seth Akkerman, Vivek Thakker, & Lauren Bozarth
A guitarist doesn't just pick up any guitar and start playing. Part of the ritual is to tune it first. It's a simple act that sets the stage for everything that follows.
And here’s what most people don’t realize: the same guitar, tuned differently, can sound like an entirely different instrument.
Large Language Models (LLMs) work in much the same way. The "tuning"—or training approach—shapes the outcomes, the responses, and ultimately, the value they bring to your organization.
The question isn’t which model you use. It’s how much you tune it and whether that last 20% is actually worth the cost.
The Instrument vs. the Tuning
Foundational models like GPT or Claude are your guitar in standard tuning. They’re versatile, reliable, and capable of playing most songs well enough. Just like a well-tuned guitar, they make a lovely sound that resonates with a wide audience.
For many organizations, that’s already 80% of the value. But then comes the temptation to retune.
Fine-tuned models are like alternate tunings. Drop D for heavier riffs, Open G for slide, or DADGAD for folk or Celtic music. In the right context, they sound incredible. They unlock precision, nuance, and performance you won’t get out of the default setup.
But they also come with tradeoffs. What makes one song shine can make another harder to play.
What “Tuning” Actually Means
In LLMs, tuning happens across a few layers:
- Pre-training is building the instrument itself, shaping its body and neck, choosing the wood, and assembling the parts. It's the foundation upon which everything else rests.
- Fine-tuning is adjusting it for a specific sound. This is where the model is tailored to perform better in certain areas—be it customer service, technical writing, or even creative storytelling.
- Reinforcement Learning from Human Feedback (RLHF) shapes what “sounds good” to humans. It's about refining those responses so they resonate more deeply with users, much like how a guitarist learns to play with emotion.
- Prompt engineering is your capo. It's fast, flexible, and often underestimated. This means you can play in different keys without much hassle, getting closer to the sound you want with minimal effort.
Not every change requires retuning the entire guitar. Sometimes you just need to play it differently.
The 80/20 Problem
Most teams can get 80% of the value from a foundation model with strong prompts and well-designed workflows. But many chase the final 20% through costly fine-tuning without asking a critical question:
Does that last 20% actually change the outcome?
Sometimes it does. If you need strict tone control, regulatory accuracy, or highly repeatable outputs (like customer support or structured workflows), fine-tuning can be worth it.
But often, it doesn’t. If your use case is internal—drafting, summarizing, ideation, general productivity—you’re usually better off improving prompts, context, and system design rather than retraining the model.
In other words: most teams don’t have a model problem. They have a usage problem.
The Real Tradeoff
A perfectly tuned, highly specialized model is powerful but narrow. A more general model, used well, is flexible—and often “good enough.”
The mistake is assuming better performance always comes from more tuning. In practice, it often comes from better orchestration:
- Clearer prompts
- Better inputs
- Smarter workflows
What This Means for Organizations
You don’t need to build a new guitar. And you probably don’t need to keep retuning it either.
You need to decide:
- What song are we trying to play?
- Where does precision actually matter?
- And where is “good enough” more than enough?
Because every layer of tuning adds cost, complexity, and maintenance. And not all of it pays off.
Every LLM can make music.
At the end of the day, every LLM makes "music." But, the goal isn’t to create the perfect instrument. It’s to get the performance you need, at the right cost, with the right level of flexibility.
Sometimes that means re-tuning. More often, it means learning how to play the instrument you already have.



