What is the best Wheel of Fortune letter to guess?

'Celebrity Wheel of Fortune' Contestant Botches This Disarmingly Easy Musical Clue, Delighting Vanna White

If you think it’s impossible to solve a Wheel of Fortune puzzle with just four letters, think again. On Thursday night, contestant Jessie Rebhan did just that when she correctly guessed the episode’s three-word-bonus puzzle with the help of just one additional letter. Rebhan’s extraordinary feat floored longtime host Pat Sajak, who remarked that “this game makes no sense at all.” After watching last week’s bizarre NSFW answer, it’s hard to argue that he’s wrong.

According to Yahoo, Thursday’s Wheel of Fortune bonus round began like any other. Rebhan, a middle school teacher from Florida, was tasked with completing the “What Are You Doing?” puzzle category, the same one that stumped contestant Marie Leo last week. The Florida native was given the standard R-S-T-L-N-E letters, three of which appeared on the board, before she had a chance to fill out the phrase. But unfortunately, Rebhan’s additions didn’t amount to much: of her P-C-D-O guesses, only “C” was correct, and she was left with a mostly-blank puzzle to solve.

“It looks daunting to me, but you know, you have 10 seconds,” said Sajak, wishing her good luck. In a remarkable turn of events, Rebhan correctly identified the final word as “juicer,” and after a brief pause, she correctly guessed the entire three-word phrase, “Buying a juicer.”

“Oh my god!” said Rebhan, after the correct answer buzzer dinged. “Of course, it’s an easy puzzle,” said Sajak sarcastically. “I don’t understand this game … This game makes no sense at all.”

Rebhan won $37,000 from the bonus puzzle, and she ended up going home with a total of $52,328. But more importantly, she went home with her pride intact, as viewers proclaimed her impossibly difficult guess “one of the most amazing solves [they’ve] ever seen.”

I have been watching Wheel of Fortune for more than 20 years now–my parents even tell me that the game taught me how to read. And all the while I have unquestionably thought that the best letters to call during the bonus round are C M D and A. But watching the program last night, I realized I had no factual basis for that. It was a belief. It was not science.

So I figured I would do some quick Googling and find out what the best letters actually were. Turns out, it seems no one has figured this out yet. (The best result was some dude on Yahoo! Answers, which wasn’t exactly reassuring.)

No problem. I found this website, which archives Wheel of Fortune bonus round puzzles and other associated information. It has a complete record from 2007-2012, or 1166 total puzzles. I scraped the data and began my analysis. Here are some of the important findings:

1) I am not a lone in my belief: C M D A are the four most frequently called letters at 64.6%, 59.9%, 57.9%, and 48.3%, respectively.

2) P H O G are the next four in order at 38.2%, 34.5%, 31.1%, and 21.0%.

3) O is the most common letter to appear in puzzles, consuming 9.5% of all letters. This just goes to show you that the bonus round puzzles are not a random sample of words from the English language–in real life, O is the fourth most common letter after E, T, and A.

4) Despite being the most common letter in English, E is the fourth most common letter in the puzzles after O, I, and A. Ostensibly, they give you R S T L N E for free because they are common letters. However, the producers intentionally pick puzzles where those letters don’t show up. Like cake, the value of R S T L N E is a lie.

5) M is an awful pick, ranking 21st on the list. It only accounts for 2.1% of the letters. Only V, J, Q, Z, and X are less frequent. No one ever calls V, J, Q, Z, or X unless they already know the answer to the puzzle and want to show off. Yet 57.9% of players pick M. Go figure.

6) H is a great selection. It has a frequency of 4.6%, placing the highest among non-R S T L N consonants. It ranks just slightly below the least frequent vowel (U, 4.7%) but higher than N (4.5%), S (3.8%) and L (3.7%).

7) If you solely want to maximize the number of letters that are revealed, H G D O is the best selection. D (3.5%) is very close to P and B (both 3.4%), so there is some wiggle room here.

To hammer home the point, the plot below shows the frequency of called letters versus what appears on the board (click to enlarge):

The mess on the bottom left corner is the V, J, Q, Z, X trash.

A couple of notes before I wrap this up. First, I want to emphasize the distinction between “most frequent letters” versus “best letters.” What shows up most frequently might not be the most useful in terms of actually solving the puzzle. G’s frequency might be overrated since a lot of those come from -ING suffixes, which you could reasonably guess if you see a word like _ _ _ _ _ N _.[1] Letters like C, B, or P might have an advantage in that they could appear at the beginning of words more frequently and are thus more valuable. This is something I could check on later.

This segues to the second point nicely. There are a bunch of interesting questions we can now answer now that I have this dataset. Expect more investigative posts like this in the future.

[1] The category What Are You Doing? only appears 9 out of 1166 times. Since this category always begins with a word ending in -ING, having the G be revealed in that slot is worthless to a contestant. But even if you remove those puzzles from the sample, G ranks much higher than the nearest alternatives.

What are the best letters to pick in Wheel of Fortune bonus round?

Are Rstlne the most common letters?

What percentage of people solve the final puzzle on Wheel of Fortune?

Why do they use Rstlne?