Another little-known, yet excellent puzzle is named Str8ts, or rather, straights. The name says it all: the puzzle is all about straights, or ranges of numbers. The main rule is that each segment, blocked off by the edges of the puzzle, or by the black cells, must contain a straight, both vertically and horizontally.

A straight, according to the rules of this puzzle, is a sequence of contiguous numbers in any order. For example, 2, 3, 1, and 4, 7, 5, 6 are both straights. Don’t confuse these with straights from the world of card games; they are two separate things. A simpler way to think of it is that skipping numbers is not allowed. If the straight contains a two and a six, for example, then it *must *contain the numbers three, four, and five. All that’s left to determine is the order of those remaining numbers.

The only other rule is that numbers must be unique in each row and column, like sudoku. This is where those blacked-out cells come in. Numbers in those cells cannot be part of any straight, but they still count for the sake of uniqueness. A number 8 in a black cell, for instance, eliminates both 8 and 9 from the row and column that cell is in. The number 8 is not allowed, and 9 couldn’t be, either, because 9 could not be a straight all by itself. Every straight has at least two numbers.

Here are some basic tips on how to solve Str8ts puzzles. First, look for the small, closed off, cramped sections of the puzzle. Start there and work your way out. Look at which numbers are available for each particular straight segment, and see if that doesn’t give you a clue about another part of the puzzle.

Numbers 1 and 9 are especially helpful, because there is only one direction the straight can extend from them. If there is a four-cell row straight with a 9 in it, for example, that means the other three numbers must be 8, 7, and 6. Using clues from the columns intersecting that row, the order can then be determined.

Also, two-cell straights are often quite easy. If one number is already known, 2 for example, the other number can only be 1 or 3. If one of those two numbers is already in that same row or column, it is safe to assume the second number is the one remaining.