Make us your home page

Today’s top headlines delivered to you daily.

(View our Privacy Policy)

Q&A: How difficulty level of Sudoku puzzles is determined

Determining Sudoku difficulty

Related News/Archive

I would like to know how the difficulty level of the Sudoku puzzles in BayLink is determined. I ask because sometimes I have a great deal of difficulty with a "medium" and at other times a "hard" is straightforward and just pleasantly challenging.

Merl Reagle supplies the Sudoku for the BayLink section of the St. Petersburg Times, so we asked him how he determines the difficulty level. He writes:

"We create our Sudokus using a variety of software and grade them using a variety of systems. When I solve them myself I find that the easy ones are always easy, but that out of every 10 mediums, two strike me as more on the hard side, and out of every 10 hards, two strike me as more on the medium side.

"There are a couple of reasons for this. For example, I might start solving a hard Sudoku in a way that happens to be the perfect strategy for that particular puzzle, and thus it will seem more like a medium. Or I may be solving a medium and I keep missing the only breakthrough point that would allow me to advance, and thus that puzzle will seem like a hard — but since the Sudoku is still a medium after I get past that one roadblock, it's graded as a medium overall.

"I have five or six strategies that I use when solving, all of which involve what I call 'quick look' logic (not the complicated extrapolating kind that the superhard Sudokus often require), and sometimes I use one of my advanced strategies early on — often without realizing it — and an otherwise hard Sudoku seems to fall much faster than usual.

"So it's a combination of how the software judges hardness and how each solver solves."

Why no All-Star Game here?

During the Major League Baseball All-Star Game, one announcer said there are only two MLB teams that haven't hosted the All-Star Game. Tampa Bay is one of them; who's the other?

The Florida Marlins and the Tampa Bay Rays are the only teams that have yet to host an All-Star Game, since the event was held in Arizona in July. There are probably two reasons for this:

• Relative newness. The Florida Marlins began playing in 1993, and the Rays began in 1998. They are two of the four most recent teams to be awarded franchises, the others being Arizona (1998) and Colorado (1993).

• Stadiums. Major League Baseball has very low opinions of the stadiums the Rays and Marlins play in.

The Marlins won't have that problem for long. Their new stadium is going up now and is expected to be ready for opening day 2012. And because of that, the Marlins are said to be in the running for the 2015 game.

The Rays have no new stadium plan in place, though it is a topic of conversation, and therefore are not expected to be considered for an All-Star Game.

To play: Fill in the grid so that every row, every column and every 3-by-3 framed box contains the numbers 1 through 9 exactly once. The solution is unique.

Yesterday's answer

Q&A: How difficulty level of Sudoku puzzles is determined 08/01/11 [Last modified: Monday, August 1, 2011 11:40pm]
Photo reprints | Article reprints

© 2017 Tampa Bay Times


Join the discussion: Click to view comments, add yours

  1. In advertising, marketing diversity needs a boost in Tampa Bay, nationally


    TAMPA — Trimeka Benjamin was focused on a career in broadcast journalism when she entered Bethune-Cookman University.

    From left, Swim Digital marketing owner Trimeka Benjamin discusses the broad lack of diversity in advertising and marketing with 22 Squared copywriter Luke Sokolewicz, University of Tampa advertising/PR professor Jennifer Whelihan, Rumbo creative director George Zwierko and Nancy Vaughn of the White Book Agency. The group recently met at The Bunker in Ybor City.
  2. Kushner to testify before two intelligence committees


    WASHINGTON— President Donald Trump's senior adviser and son-in-law Jared Kushner is set to make a second appearance on Capitol Hill — he will speak with the House Intelligence Committee on Tuesday, one day after he is scheduled to speak with Senate Intelligence Committee investigators behind closed doors.

    White House senior adviser Jared Kushner is scheduled to testify before the Senate Intelligence Committee and the House Intelligence Committee. [Associated Press]
  3. Rays blow lead in ninth, lose in 10 to Rangers (w/video)

    The Heater

    ST. PETERSBURG — Rays manager Kevin Cash liked the way Alex Cobb was competing Friday night. He liked the way the hard contact made by the Rangers batters went away after the second or third inning. So as the game headed toward the ninth, there was no doubt in Cash's mind that sending Cobb back to the mound was …

    Rays starter Alex Cobb can hardly believe what just happened as he leaves the game in the ninth after allowing a leadoff double then a tying two-run homer to the Rangers’ Shin-Soo Choo.
  4. Exhumation of Dalí's remains finds his mustache still intact


    FIGUERES, Spain — Forensic experts in Spain have removed hair, nails and two long bones from Salvador Dalí's embalmed remains to aid a court-ordered paternity test that may enable a woman who says she is the surrealist artist's daughter to claim part of Dalí's vast estate.

    Salvador Dal? died in 1989 leaving vast estate.
  5. Sessions discussed Trump campaign-related matters with Russian ambassador, U.S. intelligence intercepts show


    WASHINGTON — Russia's ambassador to Washington told his superiors in Moscow that he discussed campaign-related matters, including policy issues important to Moscow, with Jeff Sessions during the 2016 presidential race, contrary to public assertions by the embattled attorney general, current and former U.S. …

    Attorney General Jeff Sessions recused himself from the Russia investigation after meetings with an ambassador were revealed.