There's a reflex that happens in almost every company when a new hire joins: you pair them with your best person. Your top performer. The one who just gets it. The one whose judgment you trust, whose results speak for themselves.
It feels like the right call. It's almost always the wrong one.
Employee onboarding training doesn't work like most people think it does — and understanding why your best employees make the worst trainers might be the most important shift you make in how you ramp new hires this year.
The Curse of Expertise
There's a well-documented cognitive phenomenon called the "curse of knowledge." Once you know something deeply, it becomes almost impossible to remember what it felt like not to know it. You lose access to the confusion, the gaps, the false assumptions a beginner brings to the table.
Your best employee has been doing their job for three, four, maybe seven years. They've internalized processes so completely that they can't explain them — they just do them. When they try to teach, they skip steps they don't even realize they're skipping. They make intuitive leaps that feel obvious to them and are completely opaque to someone starting from scratch.
The new hire nods. They don't want to look slow. They file away the confusion to revisit later — except "later" never comes, and the confusion becomes a gap that compounds over months.
High Performers Are Expensive
Here's the business reality no one likes to say out loud: your top performer's time is the most valuable time in your company.
When you pull that person into onboarding duties — shadowing sessions, answer-every-question availability, informal mentorship that bleeds into their whole afternoon — you are making a very expensive trade-off. You're paying star-player rates for a task that is not being done well.
That's not a knock on your best employees. They didn't sign up to be trainers. Most of them don't want to be. They want to do the thing they're actually good at. Dragging them into onboarding without a real system in place isn't just ineffective — it creates resentment, disrupts their output, and doesn't even produce the results you're hoping for.
What Good Employee Onboarding Training Actually Looks Like
The assumption underneath "pair new hires with your best people" is that onboarding is a mentorship problem. It's not. It's a knowledge architecture problem.
The goal of onboarding isn't to transfer one person's intuitions to another person. The goal is to give someone a structured path through the information, processes, relationships, and context they need to do their job independently. Those are very different things.
Good employee onboarding training is:
- Documented, not improvised. The institutional knowledge lives somewhere explicit, not in someone's head.
- Role-specific, not generic. The new Head of Operations doesn't need the same onboarding path as a new SDR.
- Sequenced, not dumped all at once. Information has to arrive in the order it's actually useful.
- Verifiable. There's a way to know whether the new hire actually absorbed it, not just sat through it.
None of those qualities have anything to do with who your best performer is. They're properties of your system.
The Real Job of a Star Performer in Onboarding
Here's how top performers should be involved in onboarding: they should help build the system once, not run the same ad hoc training session fifty times.
Sit down with your best people once — record the sessions, document the playbooks, capture the judgment calls they make and why. Extract the knowledge from their heads and put it somewhere durable. That's a one-time investment that scales. Asking them to repeat it for every new hire is a recurring tax that doesn't.
Once the system exists, your top performers can show up at key inflection points — a 30-day check-in, a project debrief, a specific knowledge transfer session. High-leverage, bounded, purposeful. Not as the default support system for someone who has questions about how to submit expenses.
The Trap of Informal Onboarding
Most companies believe they have an onboarding process. What they actually have is a collection of informal behaviors that happen to recur: someone gives a tour, IT sets up accounts, a manager schedules a few intros, and then the new hire figures the rest out by asking around.
That "asking around" is where your best people get dragged in. Because they're the ones who know the answers. And because they know the answers, they become the de facto onboarding infrastructure — which means the quality of any given new hire's experience depends entirely on how accessible, patient, and articulate that person happens to be that week.
That's not a system. That's luck.
What Happens When You Fix This
Companies that build real onboarding infrastructure — documented knowledge bases, structured ramp plans, role-specific learning paths — see measurable gains in time-to-productivity. New hires get up to speed faster. Managers spend less time fielding repetitive questions. And critically, top performers stay in their lane: doing the work they're best at, not moonlighting as reluctant trainers.
There's a compounding effect too. When knowledge lives in the system rather than in people's heads, it doesn't leave when someone does. You stop rebuilding from scratch every time there's turnover. The institutional memory becomes an asset instead of a liability.
Stop Relying on Your Best People to Carry Bad Systems
The instinct to pair new hires with top performers comes from a good place — you want new people to have the best possible start. But the execution puts the burden in the wrong place and produces predictably mediocre results.
Your best employees aren't bad at onboarding because they're not generous or smart. They're bad at it because expertise makes teaching hard, because ad hoc training doesn't scale, and because you've handed them a job they were never set up to do well.
Build the system. Capture the knowledge. Get it out of people's heads and into a form that actually works for someone who's starting from zero. Your new hires will ramp faster, your top performers will thank you, and you'll stop mistaking "we have great people" for "we have a great onboarding process."
They are not the same thing.