Four Groups Guide: Spot the Red Herrings

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The first instinct is to grab the four words that jump out: four colours, four animals, four fruits. Do not. Count how many words fit that obvious theme. If you find five, you have found the red herring, and the extra word belongs somewhere else. The puzzle is built so that at least one word in the obvious group is really a member of a trickier group.

Spend thirty seconds naming, for each word, every category it could belong to. CHERRY is a fruit, a colour and a wood; TURKEY is a bird, a country and a bowling term; LEAD is a metal, a verb and a dog's leash. The words with the most possible meanings are the ones to be careful with.

Look for the hidden mechanics

Beyond simple categories, Four Groups uses a handful of recurring tricks:

• Hidden words: each word contains a smaller word (CHAIR, SPAIN, FLAIR, DAIRY all hide AIR).
• Add a letter: each word becomes something else with a letter added (BRIDE to BRIDGE, HEAT to HEART, PANT to PAINT).
• Words before or after another word: FIRE, FOOT, HAND and SNOW all go before BALL.
• Homophones: words that sound like numbers, letters or notes (WON, TOO, FOR, ATE).
• Anagrams: words that rearrange into something themed.
• Parts of a whole: parts of a bicycle, of a shoe, of a book.

If four words seem to have nothing in common as meanings, look at their letters and sounds.

Find the group with no alternatives

The safest first submission is not the easiest-looking group but the one whose four members fit nowhere else. Work through the words and ask which ones have only one plausible home. When you have four of those that share a theme, submit them. Removing four words from the board also removes their ability to confuse the rest.

Using "one away"

"One away" means three of your four were right. It does not say which three. The efficient response is not to swap one word at random but to think about which of your four is the likeliest double agent and which unused word could replace it. If you have two candidates for the swap, try the one that leaves the other words in a tidier arrangement. Each wrong submission costs a mistake, and you only have four.

Note that "one away" also tells you something about the group you did not submit: the word that did not belong has a home elsewhere, and now you know it is not where you thought.

Save the leftovers for last

The last group costs nothing to submit, because whatever is left must belong together. So the order should be: hardest group you are sure of, then the next, and the easy or obvious group near the end only if it has been purified of herrings along the way. Many solvers lose a mistake by submitting the "obvious" group first with the herring still in it.

The difficulty labels

When a group is found it is labelled Easy, Medium, Tricky or Devious. The Devious group is usually the mechanical one (hidden words, homophones, before-and-after) and usually contains the words that seemed to fit the easy groups. Once three groups are found, the last four words are the fourth group whether or not you can see what connects them; submit them and read the label.

Common mistakes

1. Submitting the first four that match. Count to five first.
2. Ignoring letters and sounds. When meanings fail, the trick is in the spelling.
3. Random swaps after "one away". Reason about which word is the double agent.
4. Forgetting the fourth mistake ends the game. Three mistakes in and unsure? Walk through every word's alternatives before submitting.
5. Using the obvious group as a warm-up. It is the most likely to contain a herring.

Glossary

• Red herring: a word that appears to fit one group but belongs to another.
• One away: three of the four submitted words share a group.
• Before-and-after: words that all precede or follow the same word.
• Hidden word: a shorter word spelled inside each longer word.
• Devious: the label of the hardest group.