Comparison · Close to Sudoku

Sudoku vs Str8ts

Str8ts is also known as Straights

A 9×9 grid split by black cells into compartments, each of which must contain a "straight" - a set of consecutive numbers in any order.

Sudoku and Str8ts are both grid-based logic puzzles you solve by pure deduction, so solvers naturally wonder how alike they really are. The short answer: Str8ts is close to Sudoku. Below we lay out what the two share, where they part ways, and whether the skills you have built on Sudoku will carry over.

  • Grid: 9×9, black-and-white
  • Closeness to Sudoku: Close
  • Also called: Straights

What is Str8ts?

A 9×9 grid split by black cells into compartments, each of which must contain a "straight" - a set of consecutive numbers in any order. Here are the rules in full:

  • As in Sudoku, no digit repeats in any row or column across the whole 9×9 grid.
  • Black cells split each row and column into compartments of white cells.
  • Each compartment must hold a straight: consecutive numbers in any order, e.g. 4-6-5-3 forms the run 3-6.
  • Black cells may carry a clue digit that is excluded from the compartments but still blocks that digit in its row and column.

What Str8ts looks like

Str8ts is played on a 9×9 board where black cells split each row and column into compartments of white cells. Every compartment must hold a straight - consecutive numbers in any order. Here is a solved row: a compartment of 3-5-4 (the run 3-4-5), a black cell, then a compartment of 7-8 (the run 7-8).

234654346785689789

A Str8ts board: black cells split each row and column into white compartments, and every compartment holds a straight - consecutive numbers in any order (here 2-3-4, 3-4-5, 6-7-8, …).

Each compartment is a Renban line by another name, on Sudoku's own 9×9 board with the usual no-repeat rows and columns. The boxes are gone, replaced by compartments - so a Sudoku solver's candidate-elimination habits transfer almost wholesale.

What Str8ts shares with Sudoku

  • It is played on the same 9×9 board with the very same "no repeats in a row or column" rule.
  • Compartments behave like Renban lines - a set of consecutive digits scrambled in order.
  • Solving leans on pencil marks and single-candidate elimination, exactly like Sudoku.

How Str8ts differs from Sudoku

  • There are no 3×3 boxes - the boxes are replaced by compartments of varying length.
  • The consecutive-run rule adds range reasoning Sudoku doesn't have.
  • Black cells and their clue digits are a structure with no Sudoku equivalent.

Do Sudoku skills transfer?

Str8ts rewards the same candidate-elimination habits as Sudoku - naked pairs and singles thin the marks - layered with the range logic of a Renban line. A Sudoku solver picks it up in one puzzle.

Brush up on the technique that carries over: Naked Pair.

The verdict

Str8ts keeps Sudoku's 9×9 row/column skeleton and swaps boxes for consecutive-run compartments - a Renban twist on familiar ground.

Prefer to stay with Sudoku?

If Str8ts appeals, these Sudoku variants scratch the same itch and you can read up on each here:


Where to play it

If it was Sudoku you came for, the level is the choice that matters more than the variant - Str8ts and Sudoku part ways on the rules, but a Sudoku grid can be a two-minute warm-up or an hour of work depending on nothing but how much of it you are given.

Difficulty and type are two separate dials here: the type sets the extra rule, the level sets how much of the grid you start with. Easy Sudoku leaves 36 of the 81 cells filled, so there is always an obvious next move somewhere; Evil Sudoku leaves 23, with no easy moves at all. Take it at the gentler end while the pattern is still new, and move up once it stops being a fight.

About Evil Sudoku

Str8ts vs Sudoku - FAQ

What is Str8ts?
A 9x9 grid divided by black cells into compartments. Each compartment holds a "straight": a set of consecutive numbers in any order, so 4-6-5-3 is valid because it covers 3 to 6. On top of that, no digit repeats in a row or column, exactly as in Sudoku.
How is Str8ts different from Sudoku?
Sudoku fills every cell with the digits 1 to 9 under row, column and box rules. Str8ts drops the box, adds black cells that break each line into compartments, and requires each compartment to be a run of consecutive numbers. The shared half is the no-repeats rule; the new half is reasoning about ranges rather than single candidates.
Do Sudoku skills carry over to Str8ts?
The elimination does: crossing out what a cell cannot be works the same way. What is new is range logic - a compartment of four cells containing a 6 can only span 3 to 9, which rules out most digits before you look at anything else.

Come for Str8ts, stay for Sudoku

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