Mike Holt accuracy test (review 3)

Why test Mike Holt in the first place

Mike Holt has been the gold standard for NEC training for decades. His books sit on every serious electrician's shelf, and his seminars fill rooms. So when you build an NEC reference app, you benchmark against Mike Holt. Not against the codebook, not against a generic chatbot. Against the guy who taught most of us how to read the code in the first place.

This is review three. Reviews one and two looked at speed and UI. This one is the brutal one: accuracy. I ran 40 real-world questions through Ask BONBON and through Mike Holt's published material (books, videos, newsletter archives, and the MH forum). Same questions, same scoring. Here's what shook out.

The test setup

Questions came from three buckets: stuff I've actually hit on the job in the last 90 days, stuff apprentices ask me on the regular, and edge cases from inspector callbacks. No gotchas, no trick questions about the 1978 code cycle.

Scoring was simple. Correct answer with correct NEC citation: full point. Correct answer with wrong or missing citation: half point. Wrong answer: zero. A wrong answer that could get someone hurt or fail inspection: negative one.

• 40 questions total
• 15 residential (branch circuits, GFCI, AFCI, service calcs)
• 15 commercial (feeders, grounding, motor circuits, 250.122)
• 10 edge cases (hotel rooms, marinas, PV systems, EVSE load calcs)

Where Mike Holt wins

Depth of explanation. Hands down. Ask Mike Holt why 210.8(A)(6) requires GFCI for kitchen receptacles and you get history, rationale, and a diagram. The man teaches. Ask BONBON gives you the rule and moves on. For an apprentice studying for the journeyman exam, Mike Holt's material is still the better teacher.

Commercial motor circuit calcs are another Mike Holt stronghold. His worked examples for 430.22, 430.24, and 430.52 are ironclad. I hit three motor questions where BONBON gave the right number but Mike Holt's explanation made the logic stick.

Tip from the field: if you're prepping for your journeyman or master exam, buy the Mike Holt workbook. No app replaces sitting down with worked problems and a pencil.

Where Ask BONBON wins

Speed and currency. Mike Holt's published books are frozen to a code cycle. If you're on the 2023 NEC and his book is 2020, you're cross-referencing manually. BONBON is on the current adopted code for your state, and it knows which amendments your jurisdiction tacks on. That matters in California, Oregon, and anywhere with state amendments that override the base NEC.

Edge cases were the real gap. I asked both sources about EVSE load calcs under 625.42 with a 48-amp charger on a panel already loaded at 78%. BONBON gave me the answer plus the demand factor logic in about four seconds. Mike Holt's material has the pieces, but I spent 20 minutes stitching them together from three different articles.

• Marina receptacle requirements under 555.33: BONBON nailed it, MH required two lookups
• Hotel guest room AFCI under 210.12(C): tie, both correct
• PV rapid shutdown 690.12(B)(2): BONBON cited 2023 language, MH book was on 2020
• Feeder tap rules 240.21(B)(2): tie on answer, MH better on reasoning

The raw numbers

Ask BONBON scored 36 out of 40. Four half-points where the citation was close but not specific enough (citing 210.8 instead of 210.8(A)(7), for example). Zero wrong answers. Zero dangerous answers.

Mike Holt's published material scored 37 out of 40. Two half-points for outdated citations (2020 code language on questions that hinged on 2023 changes), one miss on a state amendment it couldn't have known about. Zero dangerous answers.

Functionally, it's a tie on accuracy. The difference is speed and code currency versus depth of explanation.

What this means on the job

If you're in a panel at 2pm and you need to know whether that 3/0 copper feeder is sized right for a 200-amp service with a 125-foot run, you pull out your phone and ask BONBON. You don't crack a book. You don't scroll a PDF. That's the use case this app was built for.

If you're studying for a license, learning a new specialty, or trying to understand why the code says what it says, Mike Holt is still the better seat. Different tools, different jobs.

Tip from the field: use both. Mike Holt on the couch, BONBON on the ladder. The electricians I see getting promoted fastest are the ones who study at night and execute fast during the day.

Honest take

I was ready for BONBON to lose this one. Mike Holt has 40 years of field experience and a team of code experts reviewing his material. That's hard to beat on accuracy.

What I didn't expect was that code currency would close the gap so cleanly. The NEC updates every three years, and keeping a book library current costs real money and real shelf space. An app that tracks your state's adopted cycle and amendments is genuinely useful, and on four of the 40 questions, it was the deciding factor.

Next review: I'm putting BONBON up against a combined IAEI handbook and NECA standards stack. That one might actually hurt.