Optimize For Bingos In Words With Friends

See the updated version here.

Somewhere in my library of books is one called Everything Scrabble, a guide to improving your Scrabble game. I read through it a few years back and have probably forgotten half its contents, but I do remember the author's comment that highly ranked Scrabble players often swap tiles in an effort to increase their chances of hitting a bingo (a word that uses all seven letters on your tray).

I've been playing Words With Friends (screen name: linechef) and have been thinking about that Scrabble strategy. Bingoing is less of an advantage in WWF. They're only worth 35 points instead of 50, and they often open up large swaths of bonus tiles for your opponent to gobble up. But they are usually worth it if you can hit a bonus tile yourself.

Everything Scrabble provides the scoop on which five tiles you should keep in your tray to maximize bingoing, but my mind let that knowledge go into the abyss. So I decided to write a program to rediscover it.

You can imagine how the program works: Go through every seven- and eight-letter word in the Words With Friends dictionary, the ENABLE wordlist, and find every unique combination of five letters in it. Keep track of how many copies of that combination you've seen throughout the dictionary, and then sort.

Let's start with the answers first. Here are the top 20 combinations, along with the number of times they occurred (the ENABLE list has 172,823 words):

aerst 2413
eirst 2199
einst 1780
eorst 1698
eerst 1646
einrs 1596
aeist 1587
aeirs 1484
aelrs 1468
aelst 1350
aenst 1346
eilst 1338
eiprs 1286
aeirt 1273
aeprs 1266
aenrs 1258
aeins 1245
einrt 1238
deirs 1233
ainst 1232

And here's the Ruby code. Ruby 1.8.7 added a combination method to the Array class, which makes this program tiny. You tell it how big you want each subset to be, and you pass it a block which takes each subarray as an argument.

wordlist = ARGV[0]

combos_to_count = Hash.new(1)

File.open(wordlist,"r") do |file|
   line = file.gets
   while(line)
      line = file.gets      
      if line then
          line.chomp!
          next if line.length != 7 && line.length != 8
          chars = line.split(//)
          chars.combination(5) do |combo|
             combo.sort! {|a,b| a <=> b}
             combo_str = combo.join
             combos_to_count[combo_str] = combos_to_count[combo_str] + 1
          end
      end
   end
end

sorted_combos = combos_to_count.sort {|a,b| b[1] <=> a[1]}
(0...20).each {|num| puts sorted_combos[num][0] + " " + sorted_combos[num][1].to_s}

Once you have the code, you can start asking other questions. Is the list different for words with exactly seven letters? A little bit:

aerst 609
eirst 493
eorst 450
aelrs 413
eerst 404
einst 385
aeprs 379
einrs 348
aelst 346
eilst 335
acers 331
aeirs 330
aenst 327
aeist 322
deirs 320
aders 318
eiprs 317
eilrs 297
aerss 296
deers 295

Note that there are only 676 permutations of the other two letters you could fit in your tray, so with STARE you can bingo with almost any combination. I leave learning those 609 words as an exercise for the reader.

What about a different dictionary? Here's the same run I first did but with the Scrabble Official Dictionary, Third Edition.

aerst 2395
eirst 2182
einst 1759
eorst 1670
eerst 1628
einrs 1581
aeist 1562
aeirs 1473
aelrs 1458
aelst 1335
aenst 1327
eilst 1317
eiprs 1278
aeprs 1258
aeirt 1257
aenrs 1239
aeins 1232
ainst 1224
einrt 1219
deirs 1218

Of course, some of this is common sense: EST gives you the superlative of many words. Likewise, ER gives you the comparative along with the prefix RE and the "person who does" suffix. Those four letters plus vowels other than U and Y form top contenders in many of the runs.

If you're playing WWF (or Scrabble), work to keep STARE in your tray, playing or swapping other tiles, until you get a bingo. Placing it on the board, of course, is a different matter.