"Here's the story of the only truly awesome play I've ever made," Jason Katz-Brown told me when I interviewed him for my book, Brain Trust – Katz-Brown is a former US #1-ranked Scrabble player, and co-creator with John O'Laughlin of the gold-standard wordplay site Quackle, so when he talks awesome plays, less-awesome players like me listen. "There were two tiles left in the bag and I was down by, like, a hundred points, holding E-G-I-N-S-Y-Blank," says Katz-Brown. There are a lot of bingos he could've played from this bunch – words that use all seven tiles and thus score an additional fifty bonus points. "But it wouldn't have mattered," he says, "because next turn my opponent could've scored more points," and Katz-Brown would've been stuck playing catch-up again, with only the two tiles he drew from the bag as ammunition.

He computed or intuited the odds – exactly which, he's not sure – and realized that his best play was to pass and ditch his E in hope of getting a higher-value letter that would allow him to bingo out. He drew a P, for G-I-N-P-S-Y-Blank. His opponent played and drew the only remaining tile, a J. Playing off a G on the board, Katz-Brown bingoed out with "gypsying," which my spell check doesn't like, but which is most certainly included in the Official Scrabble Players Dictionary*.* Not only did he bingo out big, but his opponent had to eat the J, swinging the score by another sixteen points. "I won by, like, a few points," says Katz-Brown. Lucky as it may seem, the thing is he foresaw this as his only chance.

I’m a casual Words With Friends player, usually on my phone in bed at night, and I reciprocated with the very exciting story of my best play – the word "prejudice" off an existing "re" while playing against the computer a couple months ago. Katz-Brown was kind enough to pretend to be impressed.

This is to say that there are many levels at which WWF can be played. But according to Katz-Brown, the two basic tenets of good play are as applicable to me as they are to him: (1) know your words; and (2) be aware of the likely value of letters you leave in your rack. This is how Quackle computes word score – points plus leave value – and Katz-Brown says that when he sets Quackle to play only according to these two parameters, it can beat all but the best human players.

First, the words. After his freshman year at MIT, Katz-Brown took a summer internship in Japan (where he now works for Google). "And instead of taking advantage of, you know, Japan," he says, "I’d go back to my room and spend all night learning words." That summer, he learned all the words in the Official Scrabble Players Dictionary.

Let's imagine you're not going to do the same. Is there a way to get better at WWF with minutes – rather than months– of memorization? If you only wanted to spend time learning a handful of words, which should they be?

To find out, Katz-Brown and O'Laughlin had Quackle play itself thousands of times and looked for the best words. But these aren't simply the highest-scoring words; rather, they're the ones that allow the most advantage over other words you'd play with the same rack if you didn't know the big kahuna. For example, with an opening rack of E-H-O-P-Q-R-T, the best word is "qoph" (valued by Quackle at 46.6) and the second best word is "thorpe" (at 24.8). There's a big difference for knowing "qoph," and so it has high "playability."

In order of playability, the top forty words you absolutely must know are: qi, qat, xi, ox, za, ex, qis, ax, zo, jo, ja, xu, qadi, qaid, of, oo, if, oe, io, qua, yo, oi, euoi, oy, ow, wo, yu, fy, ee, joe, aw, we, zee, oxo, exo, axe, ye, fa, ou, ef. The first bingo on the list is "etaerio." You can find the full list with a quick search for "O'Laughlin playability."

Now to leave values, which are a bit more esoteric. Sure, it's nice to score points. But it's also nice to set yourself up to score points next time. This is what you do when you play tiles that leave compatible letters in your rack. Again, Katz-Brown and O'Laughlin engineered massive Quackle-on-Quackle action to discover the combinations that predict success on the next turn. If you're going to keep only one tile, best keep the blank (notated "?"), followed by S, Z, X, R, and H. Many of the same suspects show up in two-tile leaves, with the best being ?-?, ?-S, ?-R, ?-Z and the first without a blank being S-Z. If you're leaving three tiles, none of them blank, oh please let them be E-R-S! Other great three-tile leaves are E-S-T, E-S-Z, R-S-T, and E-R-Z. And it's likely worth ditching one letter if you can leave A-C-E-H-R-S, E-I-P-R-S-T, or E-G-I-N-R-S. You can find full lists by searching for "O'Laughlin maximal leaves."

To demonstrate the power of leave values, Katz-Brown suggests imagining an opening rack of A-E-P-P-Q-R-S. "There's no bingo, and there's no obviously exciting play that scores a lot," he says. So what should you do? Despite Q's high points and what Katz-Brown describes as most players' "animal fear of having two of the same letter in your rack," the best play is to exchange the Q. With A-E-P-P-R-S, drawing any vowel will allow you to bingo next turn.