The clue solver is probably the most powerful tool on the crosswordtools.com site and is an advanced version of the Crossword Maestro^tm technology. It uses advanced artificial intelligence techniques to solve, explain and teach cryptic and non-cryptic crossword clues! It is the product of many years of artificial intelligence research by its author, William Tunstall-Pedoe, and before it was written, solving crossword clues was considered to be something that computers were incapable of doing! This tool is an online version which enables members to access this technology simply by typing any crossword clue of their choice into a web form. Solutions are displayed instantly.

Q1. What is the purpose of this tool?

Q2. How do you use the solver?

Q3. How good is the solver?

Q4. The tool cannot solve the clue. What can I do?

Q5. What clue syntax is supported?

Q6. What types of cryptic clue are supported?

Q7. Can the clue solver solve long non-cryptic clues?

Q1. What is the purpose of this tool?

The purpose of the clue solver tool is to solve, teach and explain cryptic and non-cryptic clues. Typical situations when you might want to use it include:

• When you are completely stuck with a clue and need a solution.
• When you have the solution to a clue but don't understand how the clue works and want it explained.
• When you are having great difficult getting into a puzzle and wants solutions to a few clues to give some crossing letters.
• When you want to learn how to solve cryptic crosswords or improve your solving skills.
• When you are completely stuck with a puzzle and need a couple of solutions in order to complete the grid.
• As an independent, third-party opinion on clues that you have set yourself. (Putting it through the solver may indicate the easiness of the clue or possibly highlight areas of concern.)

Q2. How do you use the tool?

To type in a new clue, click the New Clue button. Type the clue into the "Clue" area exactly as you see it printed in the crossword and including the length description in brackets if there is one. e.g.

Judge taking tea-break after Times puzzle (8)

Select either cryptic or straight depending on the clue type and enter a letter pattern if there are any crossing letters known. This is entered as a sequence of '?' for unknown letters and the letters themselves if they are known. e.g. "??a?e??" To save time, runs of '?' can be replaced with digits. e.g. '3d4' is the same as '???d????'. When all the information is entered you can solve the clue by clicking on the Solve button.

If your clue doesn't have a length description (e.g. a straight clue from an American puzzle), enter it without a length description but make sure you enter a letter pattern even if it is all blank: i.e. a sequence of '?' characters of the right length. It is important to do this as the solver needs to know how long the answer is before it can find solutions.

After you click Solve, the solver will go to work and produce a list of possible answers. The basic philosophy of the tool is to generate as many possible answers as it can, assign a confidence score to each and give each the best explanation it can assuming that answer is correct. The answers are listed in order to maximise the chances that the correct answer will be at or near the top. The confidence percentage is designed to correspond to what the tool thinks is really the probability that this is the correct answer. i.e. An answer assigned a confidence score of 80% will be correct four times out of five. In many cases you will see that the top answer has a very high score, 99% or 100% say. When this happens the other suggested answers are very unlikely to be correct but are listed and explained anyway.

When the solve button is pressed, the clue is added to the list of previous clues. This enables you to select and re-solve it later, perhaps when you have more checked letters or after adding knowledge.

Q3. How good is the solver?

Depending on exactly how you define solve you should see the tool find the correct answer for the vast majority of typical cryptic clues. As you add checked letters, the solving percentage rises until it reaches almost 100%

The factors that influence the percentage are the quality/easiness of the clue; the number of checked letters; whether by 'solve' you mean listing the answer first, in the top five, top with a perfect explanation (etc.)

As an example, one benchmark we use is a secret (i.e. not examined by any programmer to ensure the performance is the same as with new clues) list of cryptic clues from the Daily Telegraph (mid-ranking difficulty). The tool will currently produce the correct answer and list it right at the top of the list (i.e. a very strong definition of 'solve') 55% of the time with these clues. This rises to 68% if you count times when the answer is listed in the top five solutions. As you use the correct answers to fill in the grid and re-try clues as crossing letters are added, the percentage rises to close to 100%.

We are constantly working to improve this technology and the launch of this site will also enable this to happen automatically as users add knowledge with the add knowledge tool! The vast majority of times when the solver cannot solve a clue, it is simply because there is a bit of knowledge missing. Only a tiny percentage of clues cannot be helped with this method.

Q4. The tool cannot solve the clue. What can I do?

The first thing to check is that the answer definitely isn't listed. This is easy when a few answers are shown but sometimes the correct answer is there but due to an incomplete understanding of the clue, it is listed far down the list. (When this happens, please use the add knowledge tool to help it solve it more clearly next time.)

The next thing to do is to check that you have entered a letter pattern and that all the crossing letters are correct.

If they are correct, an obvious way to improve the chances of finding the solution is to solve some of the crossing clues and get more checked letters. If you then update the letter pattern and click the 'Re-Solve' button, this information will be taken fully into account.

The following tips are more advanced techniques:

Adding Knowledge

Often you can coax the solver into solving a clue by filling in some of the possible interpretations for the parts of the clue even before you know what the answer is. For example, supposing the clue contains the phrase "as it's been spoken". This is an obvious homophone indicator but the wording is sufficiently unusual that there's a chance that it isn't listed as such in the site's knowledge base. What you can do is go to the add knowledge tool and add "so it's been spoken" as a homophone indicator. If you then return to the clue solver and click 're-solve', you may find that this is sufficient for the answer to appear.

Obviously, the same idea applies to unusual anagram indicators or translations of phrases that are sufficiently unusual to not be in the knowledge base. If in doubt, try adding them anyway. No harm is done if you add knowledge that is already in the knowledge base.

Answer appears not to be in lexicon

Sometimes there is a strong suggestion that the answer is not in the lexicon. Either the summary line says that all answers that match are listed and the answer clearly isn't there. Sometimes also the summary line will say that there are no answers which match the letter pattern/length description.

There are two possibilities when this happens. The first is that one or more of the checked letters are wrong and the second is that the intended answer does exist but the technology simply doesn’t know it.

If it’s the first possibility then the simple remedy is to check all the crossing answers carefully and try again. Sometimes the true answer is very close to what you have entered. Perhaps it is a phrase that differs from the answer that you entered by only one word.

If you have checked all the crossing answers carefully and concluded that it is the second possibility your options are more limited: the technology simply cannot suggest a word or phrase as an answer when it thinks that the word doesn’t exist. There are some things that can be done though:

If it is a single word then this is a highly unusual occurrence. The lexicon contains huge numbers of words and phrases. It is very rare to find a single word answer that it is ignorant about. When it is, it is usually a rare proper name of some sort. More commonly, however, this situation is the result of an error by the setter of the crossword and the answer is actually a two word phrase that has been labelled as a single compound word (this mistake has been observed several times). For example, the clue is:

Dealer who puts me right into fighting and singing (13)

and the checked letters are S??????R?H?N?

The tool cannot suggest any answers. You have checked the crossing clues and are certain they are all correct. What do you do?

The solution to this is simple. Insert an asterisk after the length description (i.e. (13) becomes (13*)). When you click Solve now, phrases of the required length will also be included, including the correct answer: SCRAP MERCHANT

A multi-word answer not being known is unfortunately a far more common situation. Despite the technology's unequalled knowledge of English, the number of familiar phrases is gigantic and there are still huge numbers of familiar phrases that have never been identified. The best approach to finding the answer when it is unknown to the software is to try and find the constituent words in the phrase:

For example, supposing the clue is:

Show dispassion as no usurer would (4, 2, 8)

and the checked letters are: ??k?n?i???r?s?

and supposing that the tool has told you that no answers match and you have checked all the crossing clues.

A way of making progress is to try and identify the final word which has three checked letters. Edit the letter length to become (8) and the letter pattern to become i???r?s?. (i.e. remove all trace of the other words in the phrase).

Pressing Solve now will give you a handful of possibilities, of which the only familiar word is INTEREST. Clearly this also has a link with the word Usurer in the clue (interest charged on a loan) and is almost certainly part of the answer. Now that you know that the answer is ??k? n? interest it is much easier to guess that the answer is TAKE NO INTEREST. If you were still stuck at this point you could even do the same with the first and even the second words.

When you do unravel a new phrase like this, please add it the lexicon with add knowledge tool so the facility will improve for all other members. Many thanks in advance.

Q5. What clue syntax is supported?

The general principle for the syntax of clues is that the clues should look as close as possible to how they appear in printed crosswords.

i.e. Entering the clue exactly as it appears on the printed page should work.

e.g. if the clues appears in your newspaper as:

American lawyer turns liberal, quite off the cuff (2, 3)

entering it character for character into this tool should result in it being understood.

The one novel bit of syntax that we use is the use of an asterisk (‘*’) in length descriptions. e.g.

Belief that won't change on reflection (5*)

says that although the total number of letters in the answer is 5, the number of words is unspecified. Without the asterisk it would say that the answer is a single word.

All clues must have a length description at the end in brackets, if you omit one when entering crossword clues you must enter a letter pattern of the right length, even if it is all '?' characters.

We support a wide variety of different length descriptions:

Examples:
(9) says that the answer is a single word of nine letters.
(15*) the answer is fifteen letters long and composed of one or more words.
(9, 3 words) says that the answer is nine letters long and composed of three words, where the word breaks are not specified. This syntax is found in some of the harder barred crosswords.
(9, three words) is exactly like the above.
(8, hyphenated) says that the answer is eight letters long and composed of two words with a hyphen between them. The relative length of the two words isn’t specified.
(4,5) says that the answer is made up of two words, the first four letters long and the second five letters long.
(3,4,2,3) e.g. The Land of Nod
(4-5) like the above but the words have a hyphen between them.
(5-3,5) e.g. match-box label

When solving the Crossword Maestro technology is less strict about matching words. For example there is almost no general agreement about hyphenation with many dictionaries contradicting each other. For this reason the tool will suggest answers of the required number of words and total length even its opinion of the hyphenation is different from that specified in the clue.

Q6. What types of cryptic clue are supported?

A list of indicators that are recognised by this site are here are listed here. All but the centrally positioned anagram indicator are supported by the current version of the clue solving technology. i.e. The clue solver can solve clues that use any of these types by themselves or in combination! It can also solve double definition clues and can often retrieve an answer where not all of the clue is understood.

Q7. Can the clue solver solve long non-cryptic clues?

Examples of such clues are those found in General Knowledge crosswords or some other kinds of crosswords such as the English speaking prize puzzles published in Malaysia.

The software can be of considerable help with such crosswords but you should lower your expectations a little in terms of how accurate the software will be without input from you. If we really had written computer software that could reliably parse long natural language questions on any topic, understand those questions and then produce correct answers, a crossword solver would not be our first product!

However, with some rephrasing of the clue, the software can often be made to produce the right answer. The kind of straight clue the software does well with are things like "type of dog", "part of car", "animal", "girl's name" etc. i.e. something short where the software doesn't have to do any kind of complicate parsing.

The key to making it work is for you to simplify the long natural language clue into something shorter that will include the right answer. For example, the clue:

This is commonly performed in an opera house (5)
checked letters: A????

can be simplified to:

Kind of song (5)
checked letters: A???

(what else would be performed in an opera house?) at which point the software will give you the answer ARIA (It will actually do this even without checked letters).

Another example would be the clue:

Habitual idlers .... any job that entails hard work. (5)
checked letters: S??R?

(Taken from a recent Malaysian prize puzzle.) The software is not going to do a good job with the clue in that format but you can use your intelligence to realise that the answer is going mean something similar to the word "decline". You know this because the position of the missing word in the sentence implies a verb and from the logic of the workshy declining jobs that require hard work. Thus if you rephrase the clue to simply:

decline (5)
checked letters: S??R?

and make sure it is set to straight, press Solve and you will get the two possible answers SPURN and SCORN both of which could be correct answers to the original clue.