Master Lock: All Possible 4 Letter Words

Master Lock has many different word combination locks and cable bike locks on the market that have fixed disks. (You cannot swap the order of the disks.)

In the escape room community, the three best known fixed-disk locks are:

Master Lock Model No. 1535DWD

Master Lock letter lock 1235DWD with the word "BOOK" appearing as the combination.

Master Lock Model No. 643DWD

Master Lock letter lock 643DWD with the word "MOCK" appearing as the combination.

Master Lock Model No. 175DWD

Master Lock letter lock 175DWD with the word "TEAR" appearing as the combination.

All of these fixed-disk letter locks have the exact same letter distribution, which made me wonder:

How many 4-letter words can these Master Locks create?

I hope to see more variation in solutions used on these locks in escape rooms. The same half-dozen words show up a whole lot. (I’m looking at you BURY, STAR, & SAND).

Three Master Lock letter locks with the combinations entered as sand, star, and bury.

Letter Distribution

Each fixed-disk letter Master Lock uses the following configuration:

Disk 1: L N B D M J P R S T

Disk 2: O U Y R T L H A E I

Disk 3: C D E O R S T L N A

Disk 4: K Y R S T L N E D H

What Words Can This Distribution Generate?

I asked Rich Bragg of ClueKeeper how he’d determine all the words these locks could generate. A few minutes later he sent me back a spreadsheet filled with words.

Column Explanation

There is no way to generate a single answer to the question “how many English words can this lock create?” English is a constantly evolving language. Words are created, usage shifts, and words fall into disuse.

Column A is the common English word list. This is by far the most useful column. It has 695 words.

Column B is the “ENABLE” word list. These are still words, but they are obscure or old English.

The next three columns are decreasing useful, with the fifth column being words from Wikipedia (which includes acronyms, initialisms and the like).

Each list omits the words found in the previous lists.

I’ve included all of the columns in the spreadsheet because even the less useful columns have some interesting entries… They are just few and far between.

Analysis Methodology

Bragg used TEA Crossword Helper, which is anagramming software on steroids. This is the kind of software that you use if you’re really serious about winning a major puzzle hunt.

From the TEA website:

“TEA comes with a database of over 6 million words and phrases including the title index for the English version of Wikipedia. These answers are classified by their familiarity, so you always see the most likely ones first. You can look up the meanings in the integrated dictionary/thesaurus or on the Internet. TEA is faster and more convenient than word lists in book form such as crossword completers, crossword dictionaries and crossword keys.”

Is There A Better Distribution?

The letters on each disk are pretty curious, especially when you notice oddities like the “J” in the first disk or the “Y” in the second disk.

From a letter frequency standpoint, these are not great letters to drop in those positions.

I reached out to Master Lock to ask how they chose this letter distribution, but they could not be reached for comment.

I suspect that there are more effective letter distributions possible that would generate even more words, but after a quick attempt at doing better, I fell a bit short. If you find one, I’d be curious to see it.

However, whether or not there is a better distribution, this is the one we have on these locks. It’s a lot of options. Feel free to use this list as a tool.

Master Lock Letter Lock Word List

3 thoughts on “Master Lock: All Possible 4 Letter Words

  1. I LOVE that you have done this research and posted it! Thank you!! Have you done something similar for 5-letter locks? Are there other brands or models that give other possible combinations?

  2. Hi there! I’m a first grade teacher and do lots of escape rooms in my classroom using a lock box. I NEEDED this list!!!!! THANK YOU!!!!! 🙂

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